5.56 case sizing issues

#1 · June 21, 2014, 2:34 pm

Been loading up 5.56 and noticed a problem feeding complete rounds into the AR's. Factory ammo loads and unloads without any problems. Our reloads will sometimes not completely load into the chamber and the forward assist will not push the bolt forward. When I try to remove the round, it takes considerable effort.

In comparing the reloads with the factory I noticed a slight bulge in the neck of the reload cases. At first I thought it was caused from crimping. But when I got home and checked my cases its on all the cases that I have sized, trimmed, and swaged. I have a two process setup since I need to swage, so one toolhead for the prep work and one for final reloading.

The bulge on the cases is not uniformed, some cases have it all around and most have just on half the neck. Check out the picture.

What am I missing here? I setup the sizing die just as described and checked every case with a case gage. Every case fits perfectly in the gage and all cases are trimmed to TCL of 1.750". What can I check, and can I fix the cases by resizing after figuring out what causes the bulge?

Carlton Bailey

#2 · June 21, 2014, 3:10 pm

It sounds like the size die is not down far enough. For use in semiautomatic firearms, a sized, lube-free case should drop in flush with the bottom step of the case gage. Drop a factory round into the gage, see where it stops for a comparison.

#3 · June 21, 2014, 6:29 pm

Thanks for the reply.

The die is as far down as I can get it without touching the shell plate. The clean sized cases drop right in the gage and are flush just as the factory round.

#4 · June 23, 2014, 5:27 pm

It is okay to have the die touch the top of the shellplate. If the sized, lube-free case drops flush into the case gage, then check that case in the firearm chamber. The bolt should close and the empty case should easily extract. If it does, seat a bullet, but do not crimp, and repeat both checks. It could be the seat or crimp die are not correctly adjusted.

#5 · June 23, 2014, 7:22 pm

I had this same problem when I first started reloading .223 and 5.56 and i agree with dillon, turn that die down until it touches the shellplate "firmly" I've reloaded over 10,000 rounds without a problem since this adjustment.

Good luck, Dave King

#6 · July 22, 2014, 3:54 pm

Sorry for the delay on reporting my results. Been busy doing other projects. I ran the die all the way to the shell plate. And presto, problem fixed. Thanks for the help.