I would second Winchester primers, I have been reloading for my AR for years since our agency only supplies so much ammo. The biggest thing is to make sure the primer is seated correctly. I try to stick with Winchester brass as well and take the time to trim each case to length and use a primer pocket tool to ensure a good primer seat.

So long as the primer is fully seated, you won't have a slam fire with the AR-15. The free floating firing pin does have enough inertia to contact the primer during the locking phase, but not enough to fire the round due to the timing of the locking rotation of the bolt. The round isn't actually seated on the bolt face fully until the entire action goes into battery.

You shouldn't load the same round into the chamber more than 5 times according to the TM and the manufacturer as well, due to fatigued primers being unreliable. That slow, repetitive dent can actually ruin the anvil inside the primer, making it not fire.

I used Federal GMM components whenever possible, and they never let me down.

Semperfiarms wrote:

I haven't gotten into the reloading of .223 yet. I have heard from a few guys who do that you need to make sure that you use a harder primer for it. There are some soft primers that will fire when the pin slams into it. I'll check with a buddy of mine and see which ones to use and which ones you need to stay away from. I've been reading here trying to learn as much as I can before i deploy next month. I won't be in a shooter position but there is still a lot of knowledge I can learn ahead of time. I'll be posting a couple questions once I find out from the company about my needed equipment and clothing.

Unless you forget to install the cam pin the BCG when fully or partially extended is longer than the firing pin (FP) meaning the FP will not touch the primer until the BCG cams in (unless the FP is broken and lodged in place). It is possible for inertia to cause the firing pin to kiss the primer when it cams in which could lead to a potential unplanned discharge but it wouldn't be an out of battery fire and wouldn't harm your weapon. I have heard of a few occurrences of inertia discharges but have never seen one and believe them to be extremely rare.

When reloading your .223 be sure to properly clean your primer pockets and if you are using military brass buy the pocket decrimper and remove the crimp otherwise you will not get the primer to properly seat. TBH reloading military brass is more work than its worth. If you want to reload large amounts find an indoor range frequented by yuppies who leave their once fired brass on the floor and buy it from the range or go to gun broker and get it.

As to the photo of the Bushmaster, are they sure the FP wasn't broke and stuck? I see no damage to the breach, chamber or barrel. looks like an out of battery explosion.

It wasn't out of battery. Notice the position of the extractor that was around the case rim. You won't likely see damage to the BBL, barrel extension, or much damage to the bolt other than the extractor being broken, or a few lugs sheared. Sometimes you'll see the cam pin cracked in half.

The aluminum is so much weaker that it gives way under the pressure. Compressed loads or highly overpowered loads will cause this. A primer alone isn't sufficient enough pressure to crack an upper from full battery, but ruptured cases are commonplace.