Primer blew out of case

[white121]

I have 243 lapua brass that was fired 2x in my 243 ai and when prepping for the third time I noticed that when I use the primer tool to push the primers in the case that some pushed in easier than others and on one the primer pushed in to far and way to easy, so I re sized it and decapped it, I thought mabey I pushed it in to hard and reset a primer in it and loaded the round. When I went to the range and shot my load today I had one round that when it went off it actually blew the primer out of the case and It was very scary, I expect it was the one with the faulty primer pocket so obviously I will not try that case again but my question is when I was trying different loads and watching for pressure signs I got some signs when working up the loads slight extractor marks and one pancaked primer would that pancaked primer actually stretch the primer pocket. Is your brass garbage if it gets slight pressure signs, should I get new brass, The load that this was shot out of was not a real hot load when the primer blew out it actually never had any pressure signs before hand. Any advise please other than dont load to hot, because the only time I had the real hot loads was during the load development when I started low and worked my way up.

Thanks
Shaun

 

[Preacher]

You can bet a pancaked primer will cause a loose primer pocket, any primer that slips in easy is a candidate for a toss job for the brass...
Some brass is just not good, I fireformed 50 7mmSAUM AI cases, and 2 of them showed big pressure signs and the rest were no problem at all....

 

[white121]

Thank you Preacher I was hoping you would see this because youre one of the few guys that look at everything and like to help! So I should go through and prime all my shells and any that are easier than the norm should be tossed on site.

Thank you,
Shaun

 

[JerryMay]

I had the exact same problem when I swopped from Winchester to Lapua brass. Using the same loads I had used for years in the Winchester cases gave all sorts of problems with the Lapua brass.
Loose primers, ejector scuff marks and many would not go back in the shell plate.... thought it was just me.!
October last year I helped a good friend build a .243 AI on a BAT action. Expecting Lapua Brass to be the best he puchased 200 and cut all the necks. When we started to chrono the loads with Berger 106BT and 115VLD's the Lapua cases looked ok, but come the first comp. with once fired brass the cases started to fail with a lot of primers falling out.
Well to cut a long story short he then purchased Winchester cases, cut the necks then batched for weight then worked up the load again to match the Lapua brass. We were at Bisley,UK) yesterday with his 243AI and he shot perfect, dead center V bulls all day out to 600 yards.
Just goes to show that sometimes what you take for granted as the best.....isn't.

 

[bkmilw]

Ive had similar primer,,pressuresigns), flat primers and such I always let the feel be my guide. If it doesnt feel rite or slides in way too easy you know something isnt rite. Allways trust your gut and the way things feel.

 

[white121]

Thank you very much for the help guys!

Shaun

 

[expiper]

hI Shaun....your problem is very common....if your primer says hi pressure ..then the rest of the ctg. felt it tooooo....usually when you see this or ejector marks...start marking the case heads and watch them the next time you shoot em...and or reload em...to see how tite the primer poket is...if they leak around the primer poket or blow another primer ..they ar ruint.....
This is another reason to full length re-size every time..it helps keep the bak end of the ctg from swelling out and loosing the primer poket...it is a trade off...it doesnt matter what brand of brass....and what is a max charge in Lapua may be mild in WW or UMC...or visa versa....
When you seat the primers watch evry one ...it is not just puttin in a new primer....every step in the reloading process is important and will tell the "tale" for good ammo....Roger