Iowegan’s Guide The Mysteries of for Handgun Reloaders

Powder Quality: No matter what brand, smokeless gunpowder is the most quality- controlled material you can buy. Companies just can’t afford to be wrong when it comes to burn rates or other powder attributes, especially when it is sold to the general public. When used in the right application and loaded near upper pressure limits, smokeless gunpowder has less variation than any other reloading component. Powder performance is a direct reflection of reloading techniques. When loaded in cases with inconsistent neck tension, non-uniform weights, powder weights, or at lower pressure levels, powder will burn inconsistently, which is not a fault of the powder, rather a lack of attention to detail by the person doing the reloading. Smokeless powders are extremely consistent from batch to batch, year to year, and even decade to decade.

Powder Bulk/Density: Bulk and density are opposite terms used to describe a powder’s weight versus its mass. A powder with higher bulk will fill a case more than the same weight of powder with less bulk. A powder with a higher density will weigh more than an equal volume of a different powder. Some of the classic revolver cartridges such as 38 Special, 44 Special, and 45 Colt were designed for bulky black powder. A will be more accurate if the powder has enough bulk to fill the case between the base of the bullet and the head without exceeding maximum chamber pressure, however, this is usually not possible with larger revolver cases and may result in position sensitivity.

Ignition/Burn Rate: Gunpowder is ignited by a primer flash. The intensity of the primer flash and the powder’s exposed surface area affect the initial ignition and may affect how well the powder burns after initial ignition. Powder burns best when granules are touching each other. As each granule gets ignited, that granule will in turn ignite the next granule until all powder has burned, much like a chain reaction. If there are air gaps between the granules, it can cause an erratic burn due to hesitations, which will affect chamber pressure and result in variations in velocity. Fast burning pistol powders such as Alliant Bullseye, Accurate Arms AA#2, Hodgdon Clays, and others are specially formulated where ignition and burn are quite uniform from shot-to-shot, even though the granules may not be touching. Mid burn rate powders such as Unique, AA#5, Universal, and others do not burn as uniform when granules are not touching but are still acceptable in most loads. Slow burning powders such as W-296, H-110, Lil’, IMR 4227, and others require the granules to touch or the burn will stop prematurely, resulting in a squib load.

There is a handgun powder burn rate chart page 14, which provides rank order for a host of different powders. Because powders behave differently in different sized cases and with different bullet weights, the powder’s actual burn rate can be radically different from the information in burn rate chart. The easiest way to determine powder burn rates for a specific case and bullet is to examine the loads listed in a reputable reloading manual. Assuming the same velocity, the powder that uses the lightest charge weight will be the fastest burning powder and of course, the powder that uses the heaviest charge weight will be the slowest burning powder. The Hornady manual lists their loads in order of powder burn rate. With other manuals, you will have to do some math.

1 Primers: There are two classes of primers; magnum and standard. Standard primers are intended for both fast and mid-burn rate powders. Magnum primers produce a hotter flash and are intended for slow burning powders. Within the different major brands (Federal, CCI, Winchester, and Remington), standard primer can be substituted for other brands of standard primers with virtually no difference in ignition. The same holds true for magnum primers with one exception. Winchester makes a WLP (large pistol primer) that will work for both standard and magnum loads. They are about 15% hotter than standard primers and 10% colder than magnum primers. It’s always best to use the exact primer specified in a reputable reloading manual but sometimes that is not possible. Substitution is OK but if you plan to load to max powder charges, don’t use magnum primers where a Winchester WLP is specified without backing off at least ½ grain of powder.

All powders behave differently when standard primers are specified and magnum primers are used. Magnum primers can cause fast burning powder to ignite too fast and generate pressures beyond safe limits. This can happen even with reduced powder charges. Use only standard primers for fast burning powders. Slow burning powders are doped with retardant and are much harder to ignite. Always use magnum primers with slow burning powders as specified in your reloading manual. Alliant 2400 powder is a slow burning powder with some strange characteristics so standard primers are recommended because magnum primers can cause very high-pressure spikes, especially at higher operating temperatures. Mid-burn rate powders can safely be used with either standard or magnum primers. Using a magnum primer when a standard primer is specified requires backing off the powder charge by about ½ grain.

Position Sensitivity: In larger revolver cases, fast burning powder will ignite and burn quite uniform no matter what position the powder is in. Slow burning powder usually fills the case to at least 80% capacity so they tend to be immune to position sensitivity. Mid- burn rate powder charges are the biggest problem because they seldom occupy more than 50% of case capacity in revolver cartridges and don’t burn as uniform when the granules are not touching. This means every time you fire a round, the powder inside the case repositions but never exactly the same, thus position sensitivity And erratic velocities. The surface area of the powder exposed to the primer flash can change radically from shot-to-shot. This will adversely affect pressure and velocity, making them more erratic than either fast or slow burning powders. Position sensitivity with mid-burn rate powders is not an issue in semi-auto cases because case capacity is sized right for smokeless powders.

Bullet Weights: The weight of the bullet has a dramatic affect on how powder burns. If the bullet is too light for the cartridge and the wrong powder is used, it may be pushed out of the case before the powder gets a chance to fully ignite. This will result in low or erratic velocities and both powder residue and unburned flakes of powder in the bore. Heavy for caliber make the chamber pressure increase dramatically so slow burning powder must be used to keep pressures under maximum safety limits. Bullets that are within the cartridge’s design limits tend to work the best. Faster burning powders are best for light bullets, mid-burn rate powders for normal bullet weights, and slower burning powders for heavy bullets. When you step up to magnum velocities, medium slow burn rate powders work best with light bullets and slow burning powders work best for normal or heavy bullets. The heavier the bullet, the slower the burn rate should be.

2 Chamber Pressure: This is the least understood element in reloading. Many people are taught to load for the lowest possible chamber pressure for safety purposes. Although safety is the most important factor in reloading, low chamber pressures are the primary reason why so many loads fail accuracy tests or are “fussy” and may work well in one gun and not in another. When a cartridge is developed, ammunition manufacturers conduct thorough tests to find the optimum bullet weights and powder charges that produce the best accuracy and power to work well in most any gun. With very few exceptions, factory ammunition is loaded close to the SAAMI rated maximums for each different cartridge and there are good reasons for it. Jacketed bullets require a pretty high initial pressure to overcome the friction when a bullet is first “engraved” by the rifling. With bullets, you need enough chamber pressure to force the bullet to obturate, meaning, “bump up in diameter”. If lead bullets don’t obturate, they will foul the bore and lose accuracy.

All bullets need considerable initial chamber pressures to get them started properly. After the bullet gets moving, the burn rate of the powder will determine final velocity. Fast burning powders reach peak pressure quickly then pressure drops off quickly resulting in lower muzzle velocity. Mid-burn rate powder takes a bit longer to reach peak pressure, however the pressure is maintained longer so muzzle velocity will be higher. Magnum loads use slow burning powder that takes even longer to reach peak pressure but continues to burn longer and drive bullets to high magnum velocities. All powders achieve best combustion and are most efficient at higher chamber pressures. Incomplete combustion at lower pressures result in wide variances in velocity and a dirty bore. Some powders get a bad rap for “burning dirty” when it’s really the loader’s fault for poor powder selection or poor reloading techniques.

To further complicate chamber pressure issues, testing labs have changed their test methods from the old “crusher” method to the new electronic piezo transducer method. Once piezo transducers started being used, labs found out the old method of testing was not only inaccurate, but often did not respond to fast pressure spikes. A good analogy would be testing truck tire inflation by smacking the tire with a ball bat verses testing with a tire gauge. As a result, many loads now have reduced powder charges in the newer reloading manuals. These are not “lawyer loads” as some people think, just good common sense. The old crusher method rates pressure in copper units of pressure or CUP. The new piezo method rates chamber pressure in actual pounds per square inch or psi. The Sporting Arms and Ammunition Manufactures Institute (SAAMI) sets the max pressure standards for all US made cartridges. They still maintain the old CUP standards, however these standards will slowly but surely be replaced by the new psi standards. CUP and psi are not compatible measurements and cannot be converted with a formula.

357 Magnum cartridges went through a change about the same time as the new testing methods got popular. SAAMI was petitioned to lower the pressure standards for 357 Magnums from 46,000 CUP (41,500 psi) to 35,000 psi. Both the old 46,000 CUP and the new 35,000 psi standards are current SAAMI’s standards, however nearly all reloading manuals and ammunition manufacturers have now changed to the lower pressure standard. This change extends the life of all 357 Mag revolvers and with weaker models, it makes a huge difference in longevity. CIP, the European equivalent of SAAMI, still rates the 357 Mag at 41,500 psi for European made 357 Magnum ammo.

3 Reloading Manuals: Reputable recent published reloading manuals are the key to safe and accurate loads and comply with SAAMI standards. The older manuals and many of the Internet sources use old data that often exceeds current pressure standards. If you see pressures rated in CUP, it’s old data. Loads rated in psi are new data. The best manuals are Speer #14, Hornady 7th Edition, and Sierra 5th Edition. All three of these manuals have retested most of their loads, however a few less popular loads are still rated in CUP. The best source of reloading data comes from bullet manufacturers, not powder manufacturers and there’s a good reason. Bullet style and especially bullet seating depth can make a huge difference in chamber pressure. The three companies above do their own lab tests with their own bullets so their data is much more accurate than other generic sources. If you look up the same basic loads in different manuals, likely you will find differences in powder charge weights verses velocity. This may be because the test and barrel lengths are different. Also, different brand bullets are seated to different depths, which are indicated by the cartridge overall length (COL). One manual may be using old CUP test methods or a magnum primer instead of a standard primer, etc.

Loads are displayed differently in the above manuals. For example: the Hornady manual lists their loads in order of powder burn rate for that particular cartridge, with the fastest powders at the top. The charge weights are charted in even 50 or 100 fps increments. Speer lists a starting charge and a maximum charge with the velocities for both. It’s much easier to use the Hornady manual but both have their merits. It’s always best to buy the same brand bullets as your manuals.

Pressure Signs: This is another misunderstood topic. When loading for lower pressure handgun cartridges, if you do see pressure signs, your load is already in the danger zone. Some brands of standard pistol primers will start to flatten at about 25,000 psi and by 30,000 psi, the firing pin dent may disappear. If you are loading 38 Specials, 44 Specials, 45 Colts or some other low pressure round and use the primer as a pressure guide, by the time you see primer pressure signs, you are already way over pressure … maybe double. If you use a 357 Magnum revolver to work up 38 Special loads, you may never see pressure signs because the cylinders are much stronger. Those same cartridges fired in a weaker 38 Special revolver could be a catastrophe. Case extraction and case mouth splits are also misleading. All cases swell up when fired. When pressure is excessive, the chamber will also expand. When pressure is relieved, sometime the cases seize in the chamber when the cylinder contracts. This could be a sign of over pressure or it could just be the brass you are using. Again, this is a very poor way to estimate chamber pressure. Your best method is to rely on reputable reloading manuals. Their highest listed loads are always held under SAAMI max pressure ratings providing you use the recommended primer and seat bullets to the proper COL. There is one exception … revolvers with tight cylinder throats can exceed pressure limits even if the load is rated under SAAMI maximum. If you have tight cylinder throats and like to load at the high end, you should get the throats reamed to the proper diameter.

Damage from Excessive Chamber Pressure: There are two types of damage caused by over pressure loads. Catastrophic damage is when the gun Kabooms. Long-term damage happens when “hot” loads that exceed SAAMI standards are fired over a period of time. The damage accumulates until one day when something breaks. All guns, no matter what brand, will last much longer if the loads are kept within SAAMI standards.

4 Lead versus Jacketed Bullets: Lead bullets tend to seal better in the chamber, throat, and bore than jacketed bullets. Also, it’s common for lead bullets to be .001” larger in diameter than jacketed. For these reasons, the same exact charge of powder with identical bullet weights will drive lead bullets considerably faster than jacketed bullets. At the same time, the lead bullet load will have higher chamber pressure than a jacketed bullet. It is very important to used jacketed load data for jacketed bullets and lead bullet load data for lead bullets. Usually lead and jacketed bullet data will overlap so the major safety concern is when you load at the high end of the charts.

Temperature: All smokeless powders have increased burn rates and increased chamber pressure as temperatures get higher. Reloading manuals take this into consideration and do not allow chamber pressures to exceed SAAMI maximums when the temperature of the powder is 100 deg F or less. Brass cases conduct heat very well and transfer the heat to the powder inside the case. If you leave ammo in direct sunlight or if the chamber gets hot from shooting, you could easily exceed max pressure limits. Cold temperatures under 40 deg F reduce velocity and chamber pressure. In extreme cold conditions, cartridges loaded with slow burning powder may not ignite well and could even squib. This condition could lodge a bullet in the barrel and the next round fired may blow the gun up.

Recoil: As soon as powder begins to burn, it starts creating energy, which not only pushes the bullet forward; it also pushes the gun to the rear. The total muzzle energy produced by the cartridge will produce an equal and opposite reaction in the form of recoil. Some people think the type of powder used increases or decreases recoil but it doesn’t. If you could compare two cartridges, both loaded with the same exact bullet, different powders but loaded at exactly the same velocity, recoil will be identical. If there is a difference in recoil between two loads, it’s always because one is more powerful.

Accuracy: Powder is just one of the many components that influences accuracy. The best powder selection will be the one that produces chamber pressure near the max SAAMI limits based on the weight of the bullet used and the desired velocity. The best way to measure potential performance is with a chronograph. The load that produces the most uniform velocities at near max pressures will also have the best potential for accuracy. A ten shot string over the chronograph will usually tell the story. If the max velocity spreads are tight, chances are the load will be accurate. Typical factory handgun ammo will have about a 50 fps spread between the fastest and slowest in a 10 shot string. Match grade ammo is usually under 25 fps max velocity spread. Generally, handloads with 50-75 fps spreads will be plenty accurate out to 25 yards. For bullseye competition or for shooting at greater distances, match grade loads will tighten the groups considerably.

Many times powder is blamed for inaccuracy when it’s usually some other issue such as lead bullet hardness, poor reloading techniques, exhausted brass, poor quality bullets or even the gun itself. Neck tension is the single most important issue for a good powder burn. As brass work hardens, neck tension can change dramatically. When neck tension is too light, the bullet will be pushed out of the case before all the powder ignites. The next case may have good neck tension and produce a normal velocity so when you chronograph loads where neck tension is not uniform, max velocity spreads will increase to a point where accuracy is poor. About 90% of the neck tension comes from a proper sizing die and good brass. Only about 10% of neck tension comes from the crimp die.

5 Metering: Precision powder charges make your cartridges more accurate because it keeps chamber pressure and velocity more uniform. The standard for normal loads is +or- .1 grains and +or- .05 grains for match grade loads. Some powders, such as “ball” powder tend to drop from a powder measure much more accurately than “flake” powder. If you trickle and weigh each charge, it doesn’t really matter what shape the powder granules are but if you drop powder from a measure without weighing each charge, selecting a ball type powder is going to result in more uniform powder drops. The powder’s metering attributes often determine which powder you favor.

Powder Selection: Matching the powder to the load provides the best quality possible. Powders are made in just about every burn rate and when you consider there are several powder companies, you should be able to find at least three or four different powders that will match any given application. The more skilled reloaders tend to load for several different cartridges and typically maintain a host of different powders in different burn rates. If you load for just a couple different cartridges, you can easily get by with a three different powders. Buying different powders with nearly the same burn rate is a waste of money. If you do your homework before you start reloading, you can select the best powders for your application then visit your local shop and buy one on your list.

Single Powder Concept: Many reloaders want to keep things simple and use just one powder for all their loads. This can be done but the results seldom match loads with optimum powder burn rates. If you decide to do this, use a mid-burn rate powder such as Unique, AA#5, or Universal. Powder charges can be varied to get a fairly wide range of velocities, excluding magnum levels or light target velocities. Mid-burn rate powders aren’t well suited for light target loads because chamber pressure will be too low and position sensitivity will drive max velocity spreads wild. Magnum velocities would send mid-burn rate powders over pressure. For some people, the single powder concept is fine.

Intended Purpose: Before you select a powder, you must first determine the intended purpose for the cartridges you plan to load. Applications may include: hunting small game, hunting large game, hunting dangerous game, bullseye, combat, tactical, steel silhouette, home defense, concealed carry, and of course plinking or just general purpose. The application will determine the best-suited bullet style, weight, and velocity. From that point, you can determine the best choices for powder.

Loading Regimens: There are two concepts to load for best performance … the “Work- up Concept” and the “Factory Load Concept”. The “work-up concept” is where you start at the lower end of the chart and incrementally increase the powder charge until you find optimum accuracy. This is more “fussy” and is normally used when the ammo is fired in one single gun. The “factory load concept” means you take advantage of the ammunition manufacturer’s testing and determine the velocity of factory ammo with the same bullet weight as your loads. You then select the powder where the max charge in your reloading manual produces the same velocity. This will very closely emulate factory ammo performance. These loads are not as fussy and tend to shoot well in all guns chambered for the same round, although they might not be quite as accurate as “work-up” loads in a specific gun. If you own several guns in the same caliber, the “factory load concept” is way less confusing, costs less, and you don’t have to dedicate a specific load to a specific gun. If you have a fear of shooting max pressure loads, don’t shoot factory ammo!

6 Revolvers Versus Semi-Autos: Revolvers are more robust in that you can load a spectrum of power levels and bullet weights from light target loads, to mid-range, and even up to magnum levels, all with the same revolver; assuming the revolver is chambered for magnum cartridges. Revolver operation does not depend on thrust or power levels for proper cycling like semi-autos but because revolver cases have much more capacity than semi-auto cases, position sensitivity may be an issue. With semi- autos, the power level (thrust) must be enough to cycle the action but not too much or you will damage the pistol. Semi-Auto cartridges were designed for modern smokeless powders so position sensitivity and bulk are not an issue because the cases are optimum sized. Both revolvers and semi-autos require matching powders to bullet weights and intended velocities for best accuracy and function. Some pistols, such as a 1911, can be modified with lighter/heavier recoil springs to extend the useful power spectrum.

What’s the Best Powder? This question is often seen on forums and really doesn’t have a good answer unless the intended purpose is stated along with the bullet weight, and type, barrel length, and caliber of the gun. Most long-time reloaders learn through trial and error which powders work best and which ones don’t. There is a more scientific method that will save a lot of time and is explained in the following scenarios.

Scenario #1, “Factory Load Concept”: I have a 4” Mod 10 S&W revolver rated for +P 38 Special ammunition. This revolver is in good condition and is known to be quite accurate with factory ammo. I have decided to load some 38 Special +P ammunition for self-defense. Based on preference, I want to use a Hornady 125 grain XTP jacketed hollow point bullet. I want the load to be at the optimum performance level, meaning a good power level with good accuracy but not match grade accuracy nor magnum velocity. I am using a progressive press with a built-in powder measure so powder metering is important.

My first step is to look in the Ballistic Explorer software database for factory load velocities or ammo manufacturer’s web sites. I found several companies manufacture 38 +P loads with 125 grain bullets and all are listed at 945-950 fps with a 4” barrel. The Hornady load #9032 uses this same bullet and is rated at 950 fps. This tells me several companies agree that 945-950 fps is optimum for power and accuracy for a 125 gr JHP yet loads do not exceed SAAMI 38 Special +P pressure standards.

My next step is to look up loads in a reloading manual. Because I selected a Hornady bullet, I also want to use a Hornady reloading manual so I can best emulate the factory load and seat the bullets to Hornady’s recommended depth. The Hornady manual introduction for 38 Special shows the test gun was a S&W Mod 15 with a 4” barrel so the data should match my 4” revolver fairly close. The intro page specifies Winchester WSP primers. Page 816 in the Hornady 7th Edition manual lists the loads available for the 125 grain HP-XTP bullet. The first thing I noticed was the range of velocities from 800 to 1050 fps so my desired velocity of 950 fps has several options. The footnote tells me a “star” by the powder charge indicates a +P load. Powder charges in red indicate maximum pressure loads. There are ten different powders listed and they are in order of burn rate with the fastest at the top. Note: if you look at the powder burn rate chart, the powders listed for this case and bullet are not in the same order. This is because powders behave differently in this load than when tested for generic burn rate.

7 In this particular case, I can eliminate five of the powders because they don’t reach SAAMI max pressure until the velocity is higher than I want. These powders may work just fine at lower pressures but based on previous experience, I would rather use a powder that comes closest to SAAMI max pressure at my desired velocity of 950 fps, just like they do with factory ammo. I will also eliminate Unique because it is well known for being position sensitive. 700X and Bullseye, are good options but my powder measure really likes Win 231 and AA#5 better because they are ball powders. Due to this being a lighter bullet, the faster Win 231 looks like the best choice and has a low muzzle flash. It is also a popular powder and is easy to find.

Before actually loading 5.7 grains of Win 231 I ran this load through QuickLOAD software just for confirmation. QuickLOAD predicts a velocity of 962 fps with a 4” barrel and a peak pressure of 17,149 psi. The maximum SAAMI pressure is 20,000 psi so if I went to the next highest velocity of 1,000 fps (about .3 grains higher), the load would still be slightly under maximum. My powder measure drops very uniform charges with W-231 but worst case … it could drift by as much as .3 grains and I’ll still be well within safe limits. Based on the Hornady manual, Ballistic Explorer database, and QuickLOAD, this load should perform nearly identical to Hornady’s factory load in my 4” revolver and should also work quite safely and accurately in my other 38 Special revolvers.

8 The next step is to load up a batch of 24 rounds, 10 over the chronograph, 10 on paper from a bench rest at 25 yards with 4 spares just in case. I fully expect to see an average velocity very close to 950 fps with max velocity spreads less than 50 fps. They should print 2” groups or better. I have used this technique many times in the past and have never yet been disappointed. So far, all my “factory concept loads” have performed at least as good as factory ammo, usually with better accuracy and tighter velocity spreads.

Scenario#2, “Work-up Concept”: For this example, I have a 4” GP-100 chambered in 357 Mag and I want a 38 Special load that is as accurate as possible using the Hornady 125 gr FP-XTP bullet (same chart as before). In this case, I want to work up a load with accuracy as a priority and power as secondary. This example is not as realistic as the previous one because most reloaders would use a heavier lead bullet for match grade accuracy so it’s more for an example with the convenience of using the same chart.

Looking at the Hornady manual, I see two powders with a wide range of velocity. This will come in handy should my GP-100 favor the higher velocity loads (it usually does). The two listed powders are 800X and Power Pistol. My powder measure doesn’t like 800X so I will select Power Pistol.

Based on the Hornady chart, I’m going to start with 6.1 gr of Power Pistol. I will use once fired brass for all loads. I’ll load up 12 rounds … half for the chronograph and half for a 25 yard bench rest group. I will continue to load 12 rounds in each of the increments on the chart up to 7.1 gr, marking each batch. For these small batches, I will use a single stage press and trickle up each powder charge to perfection.

At the range, I will shoot each batch over the chronograph and here’s what I expect to see: Starting with the lowest charge weight, I expect each increment will increase in average velocity by about 50 fps. Most likely, one of the loads will have a tighter max spreads than the others. Because the revolver is chambered in 357 Mag, I know I’m going to lose some velocity from the extra 1/10” of chamber so I won’t get quite as much velocity as the charts indicate. Next I’ll shoot 25 yard bench rest groups. Here again, I expect one of the batches to group tighter than the others.

If I find the group is better on the low end (usually not), I’ll go back home and load three more batches, starting with 5.4 gr, and ending with 6.1 gr. I’ll repeat the drill over the chronograph and on paper. Again, one of these batches will probably shoot better.

You may find two adjacent loads that both print the same on paper and both have about the same max velocity spread over the chronograph. As an example, let’s say it’s the 950 and the 1000 fps loads. It may just be …. a load in between the two is optimum. So again, go home and load up another test batch with 6.6 gr and try those. Some people dial in their loads to .1 grain increments. Sometimes you’ll find none of the test loads shoot as well as factory ammo. If this happens, change powder and start all over. This “work-up” concept takes a lot of time and can get expensive. When you finally have a load dialed in for your gun, chances are it won’t shoot as well in another gun. Temperature changes will affect powder burn rates so you may find the load you dialed in on a cool 50-degree day, shoots like crap on a hot 90 degree day.

9 Author’s Notes: The primary difference in the two loading concepts is the “Factory Load Concept” uses different powders to achieve the desired velocity whereas the “Work-up Concept” uses the same powder with different charge weights to find optimum accuracy. I learned the “factory load concept” more than 40 years ago and have used it extensively. I have also worked up many loads too. With very rare exceptions, I have found the “factory load concept” to be almost as accurate when loading for a single gun and much more accurate when loading the same cartridges for multiple guns. Some reloaders are reluctant to load to near-max pressures out of a reputable manual but think nothing of using different bullets and different bullet seating depths than specified in manuals. Those same people may use untested loading data or data from unreliable sources. Little do they know how safe the “factory load concept” is versus mixing components or using untested loading data. I can assure you, reputable reloading manuals test their loads thoroughly and always limit their max loads to pressures under SAAMI standards for liability reasons. If you have a fear of max pressure loads, don’t buy or shoot factory ammo!

Powder Storage: Smokeless gunpowder is a very stable compound that will last for decades if stored properly. Heat, humidity, and light are the enemies so keeping powder in a cool, dry, and dark location will ensure a long storage life. Powder should always be stored in the factory containers, never clear plastic, glass or metal. If the powder somehow gets ignited when stored in a DOT approved container, it will burn rather than explode. Avoid storing powder in GI ammo cans, safes, or other non-DOT approved outer containers. It’s best not to store powder in your powder measure for more than a few days. It can draw moisture or can be damaged by exposure to light. Check with your homeowner’s insurance for any storage quantity issues.

Shipping Powder: Shipping smokeless gunpowder is regulated by DOT regulations and is considered a Hazardous Material. By law, you cannot have more than 100 pounds of powder in one shipment. Only approved carriers can be used to ship powder and they are allowed to charge a Haz-Mat fee.

Handling Powder: Smokeless powders are less sensitive to accidental ignition from static electricity or friction than black powder; however, at some point all powder will ignite and could cause catastrophic damage. It’s always wise to take all the precautions you can to prevent an accidental ignition. Use non-sparking reloading tools made of aluminum, plastic, or pot metal. Keep those cigarettes, pipes, and cigars well away from powder. If you spill powder, consider it contaminated and dispose of it. Never have more than one container of powder on the bench at one time. Should you ever mistakenly pour one type of powder in another container, dispose of the entire contents because mixing burn rates is very dangerous. Never use a vacuum cleaner to clean up spills. A damp whiskbroom or damp rag and a dustpan work well.

Disposing of Powder: The best way to dispose of smokeless gunpowder is to sprinkle it on your yard or flowerbed. It is rich in nitrogen so it makes a good fertilizer. Never dispose of powder in a trash receptacle or any place where it could ignite.

10 One pound of powder from each of the burn rates would make an excellent bench stock that would cover most handgun cartridges on the market. There are many more brands and types of powder in each burn rate, any of which will work if these powders are not available. The powders in the three medium burn rate categories change with the size of the case so these named powders will not rate the same for all cartridges.

General Powder Applications: Burn Rate

Light revolver target load, lower velocity, and optimum accuracy: Fast Light pistol target load, lower velocity, and optimum accuracy: Medium Fast Mid-Range load, general purpose, self-defense, and gaming, good accuracy, medium power level: Medium Extended range loads, small to medium game hunting, good accuracy, higher power level: Medium Slow Magnum revolver loads, excellent accuracy, maximum power. Slow

Burn Rate Powders Velocity Fast Burning Bullseye, AA#2, 700X 700-800 fps Medium Fast Burning W-231, Clays, Titegroup 800-900 fps Medium Burning Power Pistol, Unique, AA#5 800-1000 fps Medium Slow Burning AA#9, Blue Dot 1000-1200 fps Slow Burning W-296, H-110, Lil’Gun, IMR 4227 over 1200 fps

Listed Powders: Reloading manuals do not have the luxury of testing and listing all powders that will work in a specific cartridge. Typically, the listed powders are the best performers. It’s highly recommended you use the powder and bullet listed for your intended load so the data will track properly. Using data from one source and trying to apply it to a load in a different source can get you in trouble. Even the same weight bullets in different styles or brands may have different intended seating depths that could greatly influence chamber pressure, velocity, and accuracy.

Reloading Manual Rated Velocities: If you load the precise listed loads and chronograph those loads in a very similar gun with the same barrel length, you can expect velocities in the charts to track pretty close. You may have to compensate for different barrel lengths and other mechanical differences in your gun but after compensation, if your chronograph velocities are significantly higher or lower than listed, you also have chamber pressure issues and need to investigate why.

Revolver barrel-to-cylinder gap: (B/C gap) makes a significant difference in muzzle velocity. A typical revolver has a .006” B/C gap so if yours is wider or narrower, it accounts for about a 1.5% change in velocity per thousandth of an inch difference. Shooting a load in a different type of gun will likely produce totally different velocities than listed. Example: shooting 45 ACP cartridges in a revolver versus a pistol.

Barrel length compensation: Assuming velocity is specified for a 4” barrel, compensate for actual velocity by multiplying the posted velocity by: 80% for a 2.5” barrel, 90% for a 3” barrel, 105% for a 4 5/8” barrel, 110% for a 5 ½” barrel, 115% for a 6 ½” barrel, and 120% for a 7 ½” barrel. These estimates will get you close but not exact.

11 How Smokeless Powders work

All smokeless powders are designed to operate in the “linear” portion of the pressure curve when used in the proper case and with the proper bullet weight. Powder charges that exceed limits will result in chamber pressures that are above SAAMI maximum ratings and could damage the gun. Charges below minimum pressure will result in incomplete ignition, poor accuracy and possible squibs.

The above chart shows typical powder burn characteristics for a generic revolver cartridge (not a specific load). Each different powder will have a similar characteristic chart that will change with the cartridge type, bullet weight, and even the primer. All parameters including the Squib area, Linear Propellant Range, Min Charge, Max Charge, Safety Margin, and Explosive Range will change with different powders, cartridges, or bullet weights. The concept is simple …. keep the powder charge within the minimum and maximum limits, which are listed in reloading manuals.

Squibs: All loads will have a squib range. If charges are too light, there is a risk of a “squib load”, meaning the charge doesn’t develop enough energy to push the bullet out of the muzzle. If a bullet lodges in the barrel and another cartridge is fired, it can cause catastrophic damage to the gun and may injure the shooter. With fast burning powders, the squib area is quite sensitive, meaning a charge reduced by a token amount may result in a squib. That’s because typical loads using fast burning powder don’t use much powder. Medium burn rate powders are more forgiving because they use more grains of powder but can still result in a squib if loaded under the minimum charge weight. Slow burning powders are much harder to ignite when powder charges don’t fill the case enough. It is very common to see “Do Not Reduce” cautions for H-110 or W-296 in reloading manuals for this very reason. It’s also common to see “Do Not Reduce” cautions for other case and bullet weight combinations, even with faster burning powders.

12 Linear Propellant Range: When a powder burn rate is compatible with a given cartridge, it will operate in the linear portion of the burn curve. This means when charge weights increase or decrease within the Linear Propellant Range, chamber pressure will increase or decrease by a proportional amount. The Max Charge is limited by SAAMI standards for the particular cartridge. The Min Charge is the lowest threshold to prevent squibs. Newer reputable reloading manuals always list their loads between these two limits and never exceed SAAMI standards unless noted (ie 45 Colt “Ruger & TC Only”). Older manuals that list pressures in CUP may exceed current SAAMI limits because the old testing techniques were not accurate. For jacketed bullets, optimum accuracy and velocity is almost always found near the Max Charge limit. For lead bullets, optimum accuracy and minimum bore fouling is found when chamber pressure matches lead bullet hardness. This may be well under Max Charge limits but never under Min Charge limits. Loading any cartridge under the “starting load” will result in erratic ignition, thus inconsistent velocities and possible squibs.

Safety Margin and Explosive Range: The area between the Max Charge and the Safety Margin is restricted for “proof loads” that are used at the factory to test new guns. “Hot loading” in this range may not blow your gun up but it will cause premature wear and damage. All powders have a Safety Margin, which is just below the point where powder changes from a propellant to an explosive. Once the powder charge weight exceeds this limit, chamber pressure skyrockets, resulting in a blown up gun … no exceptions. Of course the risk is much higher with fast burning powders because the case is large enough for a double charge. Note: a double charge of fast burning powder does not double chamber pressure, rather it may be ten times as much, or even more.

Because each powder has a unique Linear Propellant Range, you will get your best performance when the powder’s burn rate matches the desired velocity for your cartridge and bullet weight. When powders are mismatched for their intended purpose, performance suffers in the form of inconsistent velocity, accuracy, and fouling. Many reloaders use the same mid-burn rate powder for all handgun loads. No doubt, this will work but seldom results in optimum performance.

Powder manufacturers expend a lot of effort to provide a host of different powders that cover virtually all reloading requirements. Considering the many different manufacturers, you will have a choice of several different brands of powder with similar burn rates that match your needs. I recommend buying at least three different burn rates in the brand of your choice and availability. This will cover nearly all normal requirements. Unless you just want to experiment, there’s no reason why you should stock more than one powder in each burn rate. For fast burning powder used in handgun light target loads, Bullseye, AA#2, Red Dot, Tightwad, 700X, or Trail Boss are good choices. For medium burn rate handgun powders used in mid-range loads, W-231, Unique, AA#5, or Power Pistol, are quite good. For magnum loads, 2400, H-110, W-296, Lil’Gun, and IMR-4227 are a good choice. These are all popular powders but certainly aren’t your only choices. Reputable reloading manuals will list these and other powders with suitable propellant ranges for your desired cartridge and bullet weight; however, just because a powder is listed in a reloading manual, it doesn’t mean it will provide optimum accuracy.

13 IMR Trail Boss is a “one of its kind” powder that deserves to be detailed. Trail boss is a very fast burning powder that is shaped like small donuts to significantly increase its bulk. It was designed specifically for light target loads in large revolver cases with lead bullets. The bulk of this powder virtually eliminates position sensitivity”. Because of the extreme bulk, it doesn’t work well with semi-auto handgun ammunition.

Trail Boss has the typical attributes of other fast burning powder. It ignites very quickly and totally burns up very quickly. This provides high initial chamber pressure to force lead bullets to obturate but because it burns up so fast, pressure drops off quickly so bullets don’t have a chance to develop high velocity. This attribute makes Trail Boss an excellent selection for light target loads. It is very accurate, burns clean, and uses low charge weights. Trail Boss is not suitable for high velocity loads because chamber pressure will exceed limits. It should never be compressed and should never be loaded in excess of IMR’s load chart because fast burning powders tend to increase chamber pressure dramatically when over charged or when used with a heavier bullet.

Probably one of the best applications for Trail Boss is with novice reloaders. Because it is so bulky, it is virtually impossible to double charge a case. This attribute is also Trail Boss’s biggest safety concern because it gives a false sense of security. Trail Boss can be over charged and damage a gun just as easily as other fast burning conventional powders so use it with the same precautions. Trail Boss revolver loads can be found here: http://www.imrpowder.com/data/handgun/trailboss-feb2005.php

Popular Handgun Powder Burn Rate Comparison Chart

Fast burning: 18. Unique (Alliant) 1. Bullseye (Alliant) 19. Power Pistol (Alliant) 2. N-310 (Vihtavuori) 20. Universal (Hodgdon) 3. Tightwad (Hodgdon) 21. 800X (IMR) 4. Trail Boss 5. Red Dot (Alliant) Medium slow burning: 6. AA#2 (Accurate Arms) 22. Herco (Alliant) 7. Clays (Hodgdon) 23. HS-6 (Hodgdon) 8. 700X (IMR) 24. N-340 (Vihtavuori) 9. Nitro 100 (Accurate Arms) 25. 540 (Winchester) 26. AA#7 (Accurate Arms) Medium fast burning: 27. Blue Dot (Alliant) 10. Titegroup (Hodgdon) 11. American Select (Alliant) Slow burning: 12. Green Dot (Alliant) 28. AA#9 (Accurate Arms) 13. International (Hodgdon) 29. N-110 (Vihtavuori) 14. 231 (Winchester) 30. W-296 (Winchester) 15. HP-38 (Hodgdon) 31. H-110 (Hodgdon) 32. Lil’Gun (Hodgdon) Medium burning: 33. N-120 (Vihtavuori) 16. PB (IMR) 34. IMR-4227 (IMR) 17. AA#5 (Accurate Arms) 35. H-4227 (Hodgdon)

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