Guns: Handloading for the AR-15

In my experience, constructing .223 Remington ammunition for the AR-15 poses some unique problems.

Many are related to the AR's idiosyncratic direct impingement gas system. Load up a cartridge with too little powder, and it won't have enough juice to operate the action fully; typically this means the bolt won't lock back on the last round fired in a magazine. Depending on what type of powder is being used, a reduced load may not even feed the next round at all. Some powders are dirtier than others, which may make cleaning the AR's many small parts quite a chore.

Some are common to autoloading firearms in general. If you use heavier (and thus longer) bullets in your loads, you have to be careful that feeding isn't compromised. My typical .223 load uses a fairly vanilla 55 grain boat tail FMJ, but some of the heavy 75+ gr. match bullets are really stretching the limits of the caliber. In any case, the feeding cycle of an autoloader is pretty rough on a loaded bullet, so I crimp all my rifle cartridges.