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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 fir- ing pin. efore proceeding with load de- velopment 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 re- sults 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 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 fir- ing pin. efore proceeding with load de- velopment 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 re- sults 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.

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