Working with brass cases
- When preparing cases for cleaning, utilize a universal decapping die. Clean the cases after decapping so the primer pocket and flash hole are optimally cleaned of residues.
- How clean is clean? And does clean mean shiny? Ultimately, that's your decision.
The goal of cleaning cases is to remove debris that would negatively affect performance and accuracy. Polishing in a tumbler is an optimal step – but it sure makes the cases look nice! Inspect cases carefully after tumbling to ensure that the case mouth has not been damaged. - What’s the best method to clean brass cases? There are liquid bath solutions, ultrasonic cleaners and tumblers that may be used alone or successively. Cleaning in ultrasonic will remove more embedded dirt than a solution alone and a tumbler will both clean and polish the cases. Be sure to allow cases to dry thoroughly (we recommend overnight) before proceeding to the next reloading steps. Never place loaded ammunition in a tumbler or ultrasonic cleaner.
- When is my case wearing out? What’s the expected lifetime of a brass case? How many times can I reload a case? These questions have way too many variables associated with them to provide a casual answer. The most common visual signs of a case nearing its end of life are cracks in neck due and bulges in the case due to overwork, thinning due to impending case head separation or smiles at base due to insufficient chamber support on pistols. While there can be obvious visual cues, the uniformity of thickness of the brass must be measured to be sure of case health. Inspect cases carefully throughout the reloading process. And when in doubt – throw them out!
- Neck Sizing: An option that improves both accuracy and case life? – there has to be a catch… Neck sizing, as the name implies, resizes the neck of the cartridge, leaving the shoulder and remainder of the case at fired dimensions. Because the cartridge is just modified enough to accept a new bullet and not otherwise change, a neck-sized cartridge will be unique to the rifle it was fired in – and that’s the tradeoff. Note that full length resizing restores the cartridge to SAAMI specs and would therefore allow use in any so-chambered rifle. Carefully label neck-sized cartridges for the firearm they’re intended for.
- When deburring the case mouth, have a very light touch. The goal is to remove small burrs – not to alter the case.
- Having trouble reliably chambering pistol cartridges? Noticing that there’s an extractor groove on the rim of fired cases? Deburring the case rim may be required. Check other dimensions of the case/ammo with a cartridge gage to ensure everything else is within tolerance. If the burr on the rim is what’s keeping the case from entering the gage or chamber, carefully file off the burr. (And if it’s your pistol that’s leaving these grooves, consider having a gunsmith polish the extractor.)
- How far should the case be expanded? Just enough to accept the bullet. Expanding the case mouth too far negatively affects neck tension. Set the expander so that the bullet drops no more than 1/32” (0.03125”) into the mouth of the case. To measure this, measure the length of a representative bullet and case. Add these two numbers together. Set the expander die and run the case through it. Drop the bullet into the case and measure the overall length. Subtract this number from the previous to obtain the initial seating depth. Adjust the expander die until the 0.03125” result is achieved. (Note that a bullet comparator will produce the most accurate measurements, as it is measuring from the ogive and not a potentially malformed tip)
- How to properly crimp: Know what a good crimp looks like and crimp to meet the intended usage of the loaded ammo. Crimp cartridges as indicated in the load data to prevent bullet setback. Use a case gage to verify the crimp is right – and not excessive for calibers that headspace on the case mouth, as this condition would have the cartridge enter the chamber too deeply. Ammo for magnum revolvers and rough service require a heavy crimp to ensure that the bullets don't move in the case under recoil and transport. A normal crimp should measure 0.001-0.002” smaller in diameter at the case mouth than in the center of the seated bullet. Want to know what excessive crimp looks like? Set the crimp die too deep on purpose on an inert round so you know what to expect – which will be a damaged case.
- Crimping: Roll or taper? Bullets that have a cannelure should be seated to the cannelure and roll crimped. Straight walled pistol cartridges utilize a taper crimp – especially for those that will be magazine fed. Use dies labeled TC or taper crimp. There is also a special “factory crimp” die that is popular, but requires an additional step in the reloading process, as the seating die is not set to crimp when a factory crimp die will be utilized.
- Case length affects bullet seating depth and crimp! Excessively short cases will have too little crimp and excessively long cases will have too much crimp. Measure your cases and keep them within a 0.004” variance for target ammo and a 0.002” variance for optimal crimping on precision ammo.
Carefully selecting cases is critical to accuracy and longevity. High quality cases have more consistent dimensions and uniformity of brass thickness. Measure and record the dimensions when working with new brands of brass, lot numbers and as cases are worked throughout their life to see how they change. Sort cases by quality, selecting those with the least variance for precision ammo.
- Non-brass cases, including steel and aluminum should not be reloaded. Nickel-plated cartridges may look nice, but the hard nickel finish can damage dies over time.
- Crimped primer pockets require swaging of the primer pocket. Crimped primer pockets are often found in surplus military ammunition.