Usage Warning- Federal " AR Match" Small Rifle Primers

[catalina2014]

Picked up some primers recently and the dealer was out of my usual primers so, I accepted a 1000 of Federal"s "AR Match" Small Rifle primers. Since I was coming off .45 ACP on my Dillon 550, I went thru the usual caliber swap over. Using some rather hammered once fired cases I sized and prepped, I loaded up a few hundred V max's I had on hand and went to the range. Immediately I started having issues with my FiveSeven. Failure to ignite primers. Looking at the fired and unfired cases it appeared I was getting a lot of "light hammer strikes". Although this can be obviously caused by a weak hammer spring, dirty firing pin channel,worn firing pin, dirty chamber, safety plunger drag, and a few other things, I suspected the hammered brass might be the issue.Often times out of spec cases or bullets set out too far that contact the lands can result in a shell not seating completely in the chamber. This causes the firing action to push the shell further into the chamber, without the contact needed for ignition. After a bunch of measuring and a bit of head scratching, I decided to try some older ammo I had loaded and tested it....100% ignition! That eliminated most everything, but the primers. went to the Federal website and reading the product info found a single statement that the primers are "harder" This common in military fodder to prevent "slam fires" and is commonly encountered with the "Russian ammo" sold domestically. Switched primers and all my issues went away.

BTW contrary to what has been floated in the forum, 5.7, at least in pistol form may be loaded with either small rifle, small pistol magnum or small pistol primers. They all work in "moderate loads". If your pushing the envelope, you need to use factory new brass, since you will likely separate a neck about the same time as you pierce or pop a primer. Have seen little difference in failure point between the three primers using once fired brass. I like small rifle primers, but the others will work just fine, within reason.

[panzermk2]

All will work, but if you are laoding full power loads you need to use SR primers.

I am surprised you are having this issue with the Fed AR Match primers. I have used them in the past without issues. In fact I prefer them since they have a thicker cup and greatly reduce the likely hood of a pierced primer. Cold it be since the cup is su much thicker the primer has not been seated fully and the anvil is not touching the pie?

[catalina2014]

It would appear there in no issue with primer seating. I'm using a Dillion 550 and the primer bar is new. The failures occur in "only 10 #@&*^: % " of the loads in the FiveSeven. The primers appear to have a slightly lighter strike, have not had any issues with any other primer and the AR Match work fine .223 and 300 BLK ARs with either yellow or red JP Enterprises reduced power springs. Chamber check and case gauge both look good, so having case movement during firing sequence does not appear to be an issue either. I have an extra hammer spring in my spares kit, but it seemed easier to just switch primers.