CCI BR4 and 450 primer problems

[gunsandgunsmithing]

Hmmm. Agree it's not the best way to get an accurate measurement but it might be thin. Even so. This issue is almost always gun related. Turning the pin down and bushing the bolt almost always cures it. But..if the same gun and load didn't do it before, I'd clean the bolt internals thoroughly and check or just replace the fp spring first. Check shoulder bump too. A running start makes te problem worse than if held against the bolt face. Most of the time, it's not truly a primer problem but, ya never know until ya know.

 

[gunsandgunsmithing]

Pressure is a factor but rarely the cause of pierced or cratered primers. If they aren't very flat, it's probably not pressure related.

 

[deadidarren]

Darren,
Glad you figured this out.
Could you esplain the difference in load that was piercing primers?

Gee, now we all know the likely TRUE dimensions of the thicker CCI primers.
Wonder what a cross section of the Thinner Cup primers looks like?

Yep he has a tikka and they have a smaller diameter fp and he uses cci400 primers with a warmer load than my rifle will digest + he fl resizes.
Anyway it won't happen again as I have ordered him 10 ammo boxs in the blue colour and all mine are green .

I would also like to thank you for your efforts with cutting the primer cups it is much appreciated and just another reason I like this site so many willing to help others out .

Cheers

 

[deadidarren]

Thank you Darren for letting us know what the problem was!!! Never would have suspected mix batch error!!!

Good luck
Bill

Me neither I am 60yo and it's the 1st time .

 

[Wild Bill IV]

Me neither I am 60yo and it's the 1st time .

Shit happens!!! Don't let it bother you!!!
Just don't let it happen again!!!
And, I'm just glad nobody got hurt!!!

I'm 68, retired, and enjoying my freedom!!
You're getting close too it!!!
A year after retirement, life is good again!! But, yeah can stop being active!!!
Both in mind and body!!!
I'm applying my 105 credit hours of pure and applied science (mostly physic) into understanding internal ballistic!!! That will keep the mind going!!!!!

Once again, good luck Darren!!!!!!!!!!!!!!

 

[NC/Br Shooter]

Just think if you could reload primers!. Use a special cup that could take a beating, and fill it the same every time

 

[Rocketvapor]

Just think if you could reload primers!. Use a special cup that could take a beating, and fill it the same every time

The 0.025" cup primers can take 5.56 pressures IF the pin and headspace are correct.
It is a one and done component.
The compound in a 450 primer is about 0.3grains with a range (excluding outliers) of about 0.1grain.
Some folks SORT to 0.02grains.
How much better could you do?

People blame primer issues on the primer when it's most likely reloading or gun setup.
A lot of confusion on the CCI line of Small primers.
Like max pressure limit of the 400 vs the 450/BR4/41.
The BR4 primer is for a bolt gun. It will be about 0.004 to 0.005" shorter than the 450.
Takes a close headspace to get full ignition.