Thread: Blown primer pockets

Originally Posted by Mauser308

This is one reason Federal are so hard to get...

Reloaders have heaps now.

Primers - Reloading - Reloaders Supplies Ltd

I think you should still check headspace, it's easy to forget that there could be two problems. I had this same issue with a 20cal I had and it turned out to be both the primer and headspace. All good after throwing away a gazillion poorly sized 223 cases (fortunately all cheap military) and changing to CCI.
Try licking and sticking a piece of paper to the bottom of a case and closing the bolt. If the bolt is tight to close, you should be good, if the bolt just falls down you may have a problem. Somewhat unscientific I know, but will serve as a general indication as paper is about .004" ish. Good luck

Just came in after firing 20 rounds 10 in lapua 10 in Remington brass no more blown primers I decapped all the cases and miked the spent primers sorry this is in imperial. These are the averages the primers from the lapua measured .2117 to .2150 at the top (on the bolt head) and .2087 to .2105 in the case, the Remington cases measured .2112 to .2119 top and .2092 to .2112 in the case respectively. The blown primer measured .2164 and .213 and an unfired one measured . 2101 inches all over. Then I picked the anvils out and measured the length of the spent primers the blown one was .1099 a Remington case one was .1132, and one from a lapua case was .1084 and had a pretty noticeable mushroom head. The photo shows this I think!.
I don't have a micrometer or vernier caliper to check the size of the primer pockets but the primers seem to be backing out So I now have a supply of Federal primers coming and I'll repeat this when they get here but I'm beginning to think that the cases may also have to go.
Have just tried redbangs paper trick, tight bolt handle.

I haven't read threw the numbers but the primer in the middle looks to have a excessive headspace issue.

ok read threw numbers, lapua brass fired primers are measuring smaller where held by the case? there has to be a headspace or other issue going on here for the primer to back out of good pockets then get slammed in again.

If the primers are backing out of the brass it is to short for the chamber or the chamber is to long for the brass ie possible head space drama.

Also the load isn't hot enough to slam the case back against the bolt face once the firing pin & or plunger pushes the case forward.

If it does slam it back you will have a very flat primer like the one in the middle of the pic, which will look like an over load when possibly it isn't....