Duff primers?

[Hauptman]

Yesterday, I had a CCI small rifle primer let go and stuff a bit of brass up the firing pin hole on a Tikka 223, jamming it completely.
It was a serious workup trying to get the bolt apart......

The load was 24.7 grains of N140 behind a Berger 73 grain HPBT match bullet. I've been shooting this load for six months with with excellent results and no pressure signs/problems.

Anyone else come across this with CCI's?

H/man

[dromia]

Where did you get that load from, where is it published?

Also what is the cartridge OAL?

[dromia]

Also how did you deduce there were no pressure problems.

[StanDeasy]

I am guessing you are using CCI 400 primers. If so you need to switch to a primer with a thicker cup.

I have found these are OK : CCI 450, CCI BR4 and Rem 7 1/2

I would avoid: Rem 6 1/2 and Federal 200

[Sim G]

According to the Vhit manual, you're 0.3gn off the maximum. COL at 2.260.

[Meaty]

About 4 years back I had a couple of CCI LR primers pierce and blow back (quite disconcerting for a novice!) This was in 308 with 45.5grns N140 and 170grn Lockbase but changed over to Fed 210m's and haven't had a problem since.
More recently I have had 3 out of a batch of 40 fail to ignite when shooting my Martini Henry. Again, changed to a different make and no more problems. May just be coincidence but bloody annoying when it happens.

[greenshoots]

i have a duff run of cci primers fail to ignite 5 in a row

greenshoots

[Hauptman]

The data came from Walt Berger. It was worked up from 23 grains. The case was full-sized, and after firing showed 0.0004" increase in head diameter compared to a new unfired case. Primer pockets are showing no "stretching".
You can see from the photo that there is still a good radius around the primer.

H/man

[Hauptman]

I just measured the firing pin protrusion, and it's 1.8mm. Does this seem excessive? Having had to strip the bolt, it doesn't appear to be adjustable.
And the COAL is 2.265". Rifle has 30" barrel.

Maybe it was the warm weather................

H/man

[Meaty]

Just a thought-have you checked the size of the flash hole in the case? If its excessively large then that could be a contributing factor to the failure. The primer doesnt show any of the usual tell-tale signs of over pressure so maybe just a duff one!