How to Develop Accurate, High-Performance Handloads For

How to Develop Accurate, High-Performance Load Development Handloads for Rifles and Handguns Brian Pearce

tion and certain lever-action guns are excessively long might not cham- are generally sized in a small base ber or can cause dangerous pressures sizing die to assure proper chamber- when fired. It is preferable to begin ing. Be certain that dies are adjusted with cases from one maker and of the correctly when performing this op- same lot number, which will give the eration, or case life can be shortened most uniform results in determining and accuracy may suffer. (Most die pressure and accuracy. manufacturers offer detailed instruc- tions.) To obtain reliable chamber- Priming is an often overlooked step ing and proper bullet-to-case fit, of handloading, but plays an impor- straight-wall handgun cases should tant role in how ammunition per- Case head expansion should be checked forms. Generally primers should be using calipers that are capable of be full-length sized, and case length All cases should be carefully inspected Proper priming will assure reliable igni- Flattened primers are common with measuring 0.0001 inch. High-pressure for rifle and handgun cartridges for flaws or defects prior to handloading. tion. Most companies recommend prim- seated .003 to .005 inch below flush. factory ammunition and are not an rifle cartridges usually expand .0003 should be measured to be certain The .45-70 case on the left is new but ers to be seated .003 to .005 inch below In this fashion the anvil legs should indicator of high or excess pressure. This to .0005 inch and are generally that they are within maximum limits has a defect at the mouth, while the .45 flush, allowing the anvil to be in contact be in full contact with the bottom of Remington .308 Winchester load has a considered to be around 50,000 CUP. and trimmed if necessary. Cases that Colt cartridge is flawed due to corrosion. with the bottom of the primer pocket. the primer pocket and will give reli- flattened primer but is completely safe.

1 www.loaddata.com July-August 2007 2 How to Develop Accurate, High-Performance Load Development Handloads for Rifles and Handguns Brian Pearce

Case Inspection, Preparation and Priming able ignition when struck by the firing pin. efore proceeding with load development for any cartridge, Choosing the correct primer is also Bit is imperative to properly of paramount importance. Let’s say prepare cases. Previously fired cases we are handloading the .44 Mag- should be inspected for defects, in- num. Naturally it takes a Large Pistol cluding splits in the mouth and body. primer, but many deduct that since Look for signs of case head separation it’s a magnum cartridge it will re- (just forward of the head in the case quire Large Pistol Magnum primers. body) in the form of a shiny area on Unfortunately it is not that simple. the outside of the case, or it can be There are many excellent powders felt with a small L-shaped wire from for loading the .44 Magnum that inside the case. Cases with signs of actually give better accuracy and less corrosion may be weakened. If cases pressure when used in conjunction are older and have been stored with with standard primers. On the other fired primers in place, corrosion in- hand, there are many other powders side the primer pocket can lead to that need a Magnum primer to ig- primer pocket leakage (darkening nite correctly, and using a standard around the outer edges of a fired primer has proven (in laboratories) primer). Brass with any of the above to produce erratic pressures and ve- defects should be discarded, as it is locities. While the .44 Magnum has somewhat risky to reload. been used as an example, similar results can be seen with other cartridg- Bottleneck rifle cases are usually es, both pistol and rifle. full-length sized, while those pre- pared for semiautomatic, pump ac- Generally the best way to determine tion and certain lever-action guns are excessively long might not cham- are generally sized in a small base ber or can cause dangerous pressures sizing die to assure proper chamber- when fired. It is preferable to begin ing. Be certain that dies are adjusted with cases from one maker and of the correctly when performing this op- same lot number, which will give the eration, or case life can be shortened most uniform results in determining and accuracy may suffer. (Most die pressure and accuracy. manufacturers offer detailed instruc- tions.) To obtain reliable chamber- Priming is an often overlooked step ing and proper bullet-to-case fit, of handloading, but plays an impor- straight-wall handgun cases should tant role in how ammunition per- Case head expansion should be checked forms. Generally primers should be using calipers that are capable of be full-length sized, and case length All cases should be carefully inspected Proper priming will assure reliable igni- Flattened primers are common with measuring 0.0001 inch. High-pressure for rifle and handgun cartridges for flaws or defects prior to handloading. tion. Most companies recommend prim- seated .003 to .005 inch below flush. factory ammunition and are not an rifle cartridges usually expand .0003 should be measured to be certain The .45-70 case on the left is new but ers to be seated .003 to .005 inch below In this fashion the anvil legs should indicator of high or excess pressure. This to .0005 inch and are generally that they are within maximum limits has a defect at the mouth, while the .45 flush, allowing the anvil to be in contact be in full contact with the bottom of Remington .308 Winchester load has a considered to be around 50,000 CUP. and trimmed if necessary. Cases that Colt cartridge is flawed due to corrosion. with the bottom of the primer pocket. the primer pocket and will give reli- flattened primer but is completely safe.

1 www.loaddata.com July-August 2007 2 mum” loads. Not all guns for a given will be settled and readings will be helps establish a pattern if accuracy is cartridge share identical dimensions. more accurate. Cases should be of increasing or decreasing with powder Load Development A short throat, an abrupt leade, tight the same make, as hardness varies by and velocity increases. In this man- groove diameter or other small toler- manufacturer and so will case head ner loads can be fine-tuned to a spe- ance changes can cause pressures to expansion. Measuring the diameter cific rifle. spike in a given gun, while the same of the head, just above the extractor If this approach has not provided load was safe in the test gun or pres- slot but below the case body in the desirable results, and all possible ac- sure barrel. Excess headspace, an out- web area, before and after firing will curacy problems with the rifle have of-spec firing pin or firing pin hole give an indication of pressure. Most been eliminated, the next step is to and other issues can cause a primer modern high-velocity bottleneck car- Cases should be uniform and kept try different components including to rupture. Again, don’t start with tridges, such as the .243 Winchester, under maximum lengths or pressures This .32-20 Winchester cartridge was not bullet, powder and primer combina- maximum loads. .270 Winchester, .308 Winchester as may rise. This .30-30 Winchester case flared enough at the case mouth and buck- tions. Some guns will show a strong well as the 7mm Remington Mag- has been trimmed to 2.0295 inches, After charging cases with a “begin- led while attempting to seat the bullet. the recommended trim to length. num and similar rounds, will ex- preference with given bullets but ning” powder charge, seat bullets to pand case heads .0003 to .0005 inch might not shoot particularly well correspond with suggested SAAMI tered primers are often the result of a and are generally considered to be in problems such as a stuck bullet in with others. With experimentation, Primers should be carefully matched overall cartridge length; they should poor fitting firing pin/firing pin hole around 50,000 CUP (not psi). This the bore when a round is chambered loads can usually be developed that to the powder, or pressures can change more or less duplicate factory am- or a firing pin spring that is too weak. is approximately equal to most fac- and removed rather than being fired. will produce better accuracy than significantly. Brian suggests studying munition lengths. (More on bullet Flattened primers do not necessarily tory loads and is generally considered And some labs report a spike (or in- factory ammunition. powder manufacturers’ recommendations seating depth and overall cartridge indicate the load has excess pressure crease) in pressures in certain types of in regards to using a standard maximum. It should be noted that if ammuni- length in a moment.) or is dangerous. firearms. I do not recommend seat- or Magnum primer. Assuming your starting loads are tion is to be used in several rifles, loads Many factory loads fired in producing bullets to contact the rifling in should have similar overall specifica- below maximum pressures, fire a sporting arms, but they can usually the ideal primer for pistol cartridges tion rifles will have flattened primers. tions as factory loads to assure reliable few groups (from a proper sandbag be seated closer than factory loads. is to seek guidance from the pow- On the other hand, if one load is flat- feeding and chambering. rest) to see how that load is perform- Begin by seating the bullet out, rath- der manufacturer. The same advice tening primers more than another (at ing in your gun, then record their er long, in a dummy case and see if applies to rifle cartridges, but logic least if primers are of the same type Tips for Developing sizes. In an attempt to fine-tune the it will chamber in your rifle. If the would dictate that large capacity and and manufacture), it is probably load, seating bullets out closer to the round won’t readily chamber, turn Revolver and Pistol most magnum rounds will perform generating more pressure. Another the die’s seater stem one turn deeper better with a hotter Magnum primer, issue that can flatten primers exces- Cartridge Loads and again seat the bullet about .0300 while smaller capacity and non-mag- sively is excess headspace. If any of inch deeper, then gently try to cham- The majority of pistol and revolv- num rounds are generally best served the above issues appear with your ber the round. er cartridges operate at much lower with standard primers. After deter- factory ammunition or handloads Choosing a suitable sizing die will help that are within normal load specifi- pressures than modern bottleneck mining what powder (or powders) Through trial and error, the exact rifle cartridges. For example, the .38 will be used, then the correct primer assure proper chambering of loaded cations, you should have a qualified maximum overall cartridge length rounds. The Hornady .223 Remington gunsmith examine your rifle before Special has an industry maximum can be chosen. can be determined for a specific rifle. average pressure of 17,000 psi, the dies are “full length” making them suit- proceeding. The bullet should be at least .0010 able for most bolt actions, etc., while the .44 Special 15,500 psi, the .45 Colt inch off the rifling. Please note that Developing Loads for RCBS “small base” dies are best for au- At this point a blade-type caliper This .223 Remington handload exceeds 14,000 psi, while magnum rounds High-Pressure Bottle- toloading, pump and lever-action rifles. that is capable of measuring 0.0001 overall cartridge length recommenda- the ogive profile of bullets varies such as the .41 and .44 Remington inch will prove a valuable tool in tions of 2.260 inches and may not work considerably from one maker to the Magnums generate 36,000 psi. The neck Rifle Cartridges next and from one style to another. Fire a few rounds, carefully check- determining the safety and approxi- in some guns, but the rifle it was tailored .45 ACP runs 21,000 psi or less. The to readily chambers and regularly The point being the overall cartridge After cases are inspected, sized, ing each case for signs of excess pres- mate pressure of your handload. If point being, most handgun loads produces ½ MOA groups. length will necessarily change from trimmed (if necessary) and primed, sure. (This is where a chronograph you are using new, unfired cases to are low pressure when compared one bullet to the next to prevent bullet’s begin developing a load. Un- is valuable in determining if a load develop your new load, case head to bottleneck rifle cartridges and it rifling will often, but not always, lets from contacting rifling. Again, less one has education and experi- is close to duplicating factory loads expansion may vary more than cases is difficult to accurately assess pres- increase accuracy. The maximum record the group sizes after each ence at developing loads, published or the advertised velocity of the load that have been once-fired prior to de- sures. The difference in case head overall cartridge length (or just how change. (Seating bullets closer to data should always be referenced. you have selected. If speed is similar veloping loads. It is better to begin expansion, at least on most cases, is far we can seat bullets out) is usually the rifling often improves accuracy, Do not use loads from unknown (and with correct powders), pressure with once-fired cases, as their webs undetectable using blade calipers (for determined by two factors in typical but not always. Occasionally rifles sources, which seems prevalent on is probably similar too. Contrary example, a .38 Special load that is bolt-action repeating rifles. First, bul- will shoot better with bullets seated the Internet. Most reloading manu- to what has been widely published, generating 15,000 psi versus another lets must fit and function correctly in deeper.) als list powder charges that have been primer appearance is not always a that is producing 25,000 psi). Care- the magazine, and second they must carefully pressure tested. The “begin- good indicator of pressures, as there The next logical step is to increase ful examination of primers can help chamber properly. Single-shot rifles ning” or “starting” loads are usually are simply too many variables. None- the powder charge, typically in 0.5- determine if one load is producing are only affected by overall cartridge at least 5 percent below maximum. theless there should be no signs of grain increments in small cases such more or less pressure than another. A length, while tubular magazine guns Having experience at developing rupturing. Primers that are pierced as the .22 Hornet and .223 Reming- flattened primer is probably produc- (leverguns, pumps, etc.) must feed handloads for more than 150 differ- and/or cratered (wherein the firing ton, while cases similar in capacity to ing greater pressure than one that is correctly and are sensitive to overall ent cartridges and many more guns pin indentation is pushed back) can the .30-06 can be increased one grain “rounded” at the edges, but standard Ruptured primers are not always indicative cartridge length. than that, I must emphasize the im- indicate excess pressure but is often that a load is developing excess pressures. at a time. Again, carefully check case pressure loads in the .38 Special, .44 portance of beginning with “start- due to a rough firing pin that is in- A sloppy fitting firing pin or one that is Seating bullets out until they con- head expansion using blade calipers Special and .45 Colt cartridges will ing” loads before attempting “maxi- correctly shaped or too long. Cra- too long can cause primers to rupture. tact the leade or rifling often results and keep accuracy records. This generally all have rounded edges.

3 www.loaddata.com July-August 2007 4 mum” loads. Not all guns for a given will be settled and readings will be helps establish a pattern if accuracy is cartridge share identical dimensions. more accurate. Cases should be of increasing or decreasing with powder Load Development A short throat, an abrupt leade, tight the same make, as hardness varies by and velocity increases. In this man- groove diameter or other small toler- manufacturer and so will case head ner loads can be fine-tuned to a spe- ance changes can cause pressures to expansion. Measuring the diameter cific rifle. spike in a given gun, while the same of the head, just above the extractor If this approach has not provided load was safe in the test gun or pres- slot but below the case body in the desirable results, and all possible ac- sure barrel. Excess headspace, an out- web area, before and after firing will curacy problems with the rifle have of-spec firing pin or firing pin hole give an indication of pressure. Most been eliminated, the next step is to and other issues can cause a primer modern high-velocity bottleneck car- Cases should be uniform and kept try different components including to rupture. Again, don’t start with tridges, such as the .243 Winchester, under maximum lengths or pressures This .32-20 Winchester cartridge was not bullet, powder and primer combina- maximum loads. .270 Winchester, .308 Winchester as may rise. This .30-30 Winchester case flared enough at the case mouth and buck- tions. Some guns will show a strong well as the 7mm Remington Mag- has been trimmed to 2.0295 inches, After charging cases with a “begin- led while attempting to seat the bullet. the recommended trim to length. num and similar rounds, will ex- preference with given bullets but ning” powder charge, seat bullets to pand case heads .0003 to .0005 inch might not shoot particularly well correspond with suggested SAAMI tered primers are often the result of a and are generally considered to be in problems such as a stuck bullet in with others. With experimentation, Primers should be carefully matched overall cartridge length; they should poor fitting firing pin/firing pin hole around 50,000 CUP (not psi). This the bore when a round is chambered loads can usually be developed that to the powder, or pressures can change more or less duplicate factory am- or a firing pin spring that is too weak. is approximately equal to most fac- and removed rather than being fired. will produce better accuracy than significantly. Brian suggests studying munition lengths. (More on bullet Flattened primers do not necessarily tory loads and is generally considered And some labs report a spike (or in- factory ammunition. powder manufacturers’ recommendations seating depth and overall cartridge indicate the load has excess pressure crease) in pressures in certain types of in regards to using a standard maximum. It should be noted that if ammuni- length in a moment.) or is dangerous. firearms. I do not recommend seat- or Magnum primer. Assuming your starting loads are tion is to be used in several rifles, loads Many factory loads fired in producing bullets to contact the rifling in should have similar overall specifica- below maximum pressures, fire a sporting arms, but they can usually the ideal primer for pistol cartridges tion rifles will have flattened primers. tions as factory loads to assure reliable few groups (from a proper sandbag be seated closer than factory loads. is to seek guidance from the pow- On the other hand, if one load is flat- feeding and chambering. rest) to see how that load is perform- Begin by seating the bullet out, rath- der manufacturer. The same advice tening primers more than another (at ing in your gun, then record their er long, in a dummy case and see if applies to rifle cartridges, but logic least if primers are of the same type Tips for Developing sizes. In an attempt to fine-tune the it will chamber in your rifle. If the would dictate that large capacity and and manufacture), it is probably load, seating bullets out closer to the round won’t readily chamber, turn Revolver and Pistol most magnum rounds will perform generating more pressure. Another the die’s seater stem one turn deeper better with a hotter Magnum primer, issue that can flatten primers exces- Cartridge Loads and again seat the bullet about .0300 while smaller capacity and non-mag- sively is excess headspace. If any of inch deeper, then gently try to cham- The majority of pistol and revolv- num rounds are generally best served the above issues appear with your ber the round. er cartridges operate at much lower with standard primers. After deter- factory ammunition or handloads Choosing a suitable sizing die will help that are within normal load specifi- pressures than modern bottleneck mining what powder (or powders) Through trial and error, the exact rifle cartridges. For example, the .38 will be used, then the correct primer assure proper chambering of loaded cations, you should have a qualified maximum overall cartridge length rounds. The Hornady .223 Remington gunsmith examine your rifle before Special has an industry maximum can be chosen. can be determined for a specific rifle. average pressure of 17,000 psi, the dies are “full length” making them suit- proceeding. The bullet should be at least .0010 able for most bolt actions, etc., while the .44 Special 15,500 psi, the .45 Colt inch off the rifling. Please note that Developing Loads for RCBS “small base” dies are best for au- At this point a blade-type caliper This .223 Remington handload exceeds 14,000 psi, while magnum rounds High-Pressure Bottle- toloading, pump and lever-action rifles. that is capable of measuring 0.0001 overall cartridge length recommenda- the ogive profile of bullets varies such as the .41 and .44 Remington inch will prove a valuable tool in tions of 2.260 inches and may not work considerably from one maker to the Magnums generate 36,000 psi. The neck Rifle Cartridges next and from one style to another. Fire a few rounds, carefully check- determining the safety and approxi- in some guns, but the rifle it was tailored .45 ACP runs 21,000 psi or less. The to readily chambers and regularly The point being the overall cartridge After cases are inspected, sized, ing each case for signs of excess pres- mate pressure of your handload. If point being, most handgun loads produces ½ MOA groups. length will necessarily change from trimmed (if necessary) and primed, sure. (This is where a chronograph you are using new, unfired cases to are low pressure when compared one bullet to the next to prevent bullet’s begin developing a load. Un- is valuable in determining if a load develop your new load, case head to bottleneck rifle cartridges and it rifling will often, but not always, lets from contacting rifling. Again, less one has education and experi- is close to duplicating factory loads expansion may vary more than cases is difficult to accurately assess pres- increase accuracy. The maximum record the group sizes after each ence at developing loads, published or the advertised velocity of the load that have been once-fired prior to de- sures. The difference in case head overall cartridge length (or just how change. (Seating bullets closer to data should always be referenced. you have selected. If speed is similar veloping loads. It is better to begin expansion, at least on most cases, is far we can seat bullets out) is usually the rifling often improves accuracy, Do not use loads from unknown (and with correct powders), pressure with once-fired cases, as their webs undetectable using blade calipers (for determined by two factors in typical but not always. Occasionally rifles sources, which seems prevalent on is probably similar too. Contrary example, a .38 Special load that is bolt-action repeating rifles. First, bul- will shoot better with bullets seated the Internet. Most reloading manu- to what has been widely published, generating 15,000 psi versus another lets must fit and function correctly in deeper.) als list powder charges that have been primer appearance is not always a that is producing 25,000 psi). Care- the magazine, and second they must carefully pressure tested. The “begin- good indicator of pressures, as there The next logical step is to increase ful examination of primers can help chamber properly. Single-shot rifles ning” or “starting” loads are usually are simply too many variables. None- the powder charge, typically in 0.5- determine if one load is producing are only affected by overall cartridge at least 5 percent below maximum. theless there should be no signs of grain increments in small cases such more or less pressure than another. A length, while tubular magazine guns Having experience at developing rupturing. Primers that are pierced as the .22 Hornet and .223 Reming- flattened primer is probably produc- (leverguns, pumps, etc.) must feed handloads for more than 150 differ- and/or cratered (wherein the firing ton, while cases similar in capacity to ing greater pressure than one that is correctly and are sensitive to overall ent cartridges and many more guns pin indentation is pushed back) can the .30-06 can be increased one grain “rounded” at the edges, but standard Ruptured primers are not always indicative cartridge length. than that, I must emphasize the im- indicate excess pressure but is often that a load is developing excess pressures. at a time. Again, carefully check case pressure loads in the .38 Special, .44 portance of beginning with “start- due to a rough firing pin that is in- A sloppy fitting firing pin or one that is Seating bullets out until they con- head expansion using blade calipers Special and .45 Colt cartridges will ing” loads before attempting “maxi- correctly shaped or too long. Cra- too long can cause primers to rupture. tact the leade or rifling often results and keep accuracy records. This generally all have rounded edges.

3 www.loaddata.com July-August 2007 4 Load Development

Many handguns are not especially strong, and firing loads that exceed their recommended pressure limits can cause damage to the gun and may be dangerous for the shooter (and explains why so much emphasis is put on knowing pressures). Always use credible published data and pay particular attention to the details. For example, using a .44 Magnum load exactly as shown but with the wrong primer can increase pressures by up to 11,000 psi. Also changing or sub- Only handloading data from credible sources should be considered. Brian suggests stituting bullets of the same weight current reloading manuals or data from dedicated journals such as Handloader. can significantly change pressures, but the increased pressure is very dif- case preparation, priming, powder propellants, such as Winchester 231, ficult to detect by most handloaders. charge, bullet seating and crimping Alliant Red Dot and Bullseye, will Another common mistake includes will aid in providing consistent and generally give excellent results. Like- incorrect seating of bullets. Hornady accurate ammunition. wise these medium to fast burn rate and Speer offer 300-grain .44 Mag- One problem that occasionally powders will also give top results in num bullets with a double cannelure, surfaces with straight-wall revolver short, fat pistol cartridges such as the and there has been much data devel- cartridges includes the case mouth .45 ACP and .40 S&W. oped for the Ruger Redhawk with “biting” into cast bullets during the the bullet seated out and crimped in Commercial bullet companies such seat/crimp operation, which is often the lower cannelure. If these bullets as Hornady, Speer, Nosler, Sierra, performed as one step. First make are seated in the upper crimp groove, Barnes (actually solid copper) and certain that the case mouth is being pressures will increase substantially others offer top-rate jacketed bullets expanded sufficiently, which will al- and will probably be dangerous if the that generally shoot accurately in a low the bullet’s base to be started into powder charges are not decreased. variety of handguns, although some the case at least 1/16 inch and some- Again, attention to detail will help guns may have a distinct preference times as much as 1/10 inch. If the die assemble safe loads. for one over another. Trying each is adjusted correctly and the problem will help determine if your gun has With the above warnings out of the exists, bullets will need to be seated a preference. way, following are some suggestions without any crimp applied, then as a to develop accurate, high-performing separate step the crimp applied. When it comes to cast bullets, de- loads for your favorite handgun. signs and quality, commercial offer- Today there are dozens of great ings vary so much that results can Begin with dies that are correctly powders suitable for handloading re- range from extremely poor to excel- dimensioned. The sizer die must volver and pistol cartridges. Choose a lent. A complete discussion could fill reduce cases enough to allow prop- powder designed to burn in the opti- volumes, but suffice to say that using er chambering and securely hold mum range for a given cartridge. Full- proven designs that have been around the new bullet. The expander ball house magnum revolver cartridges for many decades will generally give should measure at least .004 inch (such as .357, .41 or .44 Magnums) the best results. (There is a reason smaller than bullet diameter to ob- will thrive on slow-burning (relative- certain cast bullet designs and loads tain proper bullet pull. (Some older ly speaking) powders such as Hodg- have become and have remained dies had issues in these areas, while don H-110, Lil’Gun, Alliant 2400, popular for generations.) recently manufactured dies are gen- Winchester 296 or Western Pow- erally good.) Revolver cartridges ders/Ramshot Enforcer, Vihtavuori The same as rifles, handgun loads should receive a heavy roll crimp, N110, etc. Cartridges such as the .45 should be checked for accuracy from but not so heavy that damage to the Colt, .44 and .38 Specials or Mag- a proper rest or comfortable shoot- bullet or buckling or bulging of the num revolver cartridges loaded with ing position. Again, through experi- case results. Autoloading cartridges, midrange or reduced loads will thrive mentation of bullet designs, weights, such as the .45 ACP, should be taper on medium burn rate powders such powder types and charges, handloads crimped to original specifications, as Alliant Unique and Power Pistol, can duplicate and even exceed fac- as it headspaces on the case mouth. Hodgdon Universal Clays or similar tory load performance in terms of ac- Focusing on uniformity starting with powders. And even faster burning curacy and velocity. • 5 www.loaddata.com