.223 primer blowback/gas leakage.

[Mark611]

JMO, 15yr old primers? How do you explain old mil surp ammo from WW2 or WW1 that's still around that folks shoot that doesn't do that? I have had some experience with primers burning holes in them or blowing completely out of the primer pocket from shooting a rifle after it was cleaned, I must have not gotten all the solvents removed from the chamber or bore? if that's not your issue? IMO the brass has been over worked in the primer pocket and has got to lose; I do not touch my primer pockets after I had those problems back then, even though the ammo I had problems with was factory loaded! I recently processed a bunch of 5.56 brass and had to remove the PP crimps, I used a tool used on case prep station chucked up in a drill and cut the crimp out of them! so far, I have had no problems with the pockets, but I'm only running 26gns of TAC under a 55gnFMJ, JMO.

 

[Cfshooter]

I was just going to ask about his situation. My Tikka bolt face is all but ruined. I am using some old Winchester primers (10-15 yrs old) and the photos speak for themselves. Just for the record Im using Accu 4064 behind 168 gr MK's. The max load is 46.5 grn, but I am loading between 44. and 44.6 grns of powder. Well below max. These bullets were jam-.020. Headspace, neck clearance, shoulder bump all were where they should be.

Was using twice fired and annealed Federal and Lake City brass. On the last shot I found my ejector arm in the bottom of the chamber. What else could it be other than the primers. I clean my pockets and primer holes consistently. Let me know what you guys think.
View attachment 1603316



View attachment 1603318

Over reamed primer pockets is Winchesters go to.

 

[markm87]

if that's not your issue? IMO the brass has been over worked in the primer pocket and has got to lose;

I prime all of this stuff with the Sinclair. So I get a good feel for any loose pockets. I mark any that feel loose with a sharpie.

I just kiss the crimp with the hornady cutter, and don't mess with the pockets beyond that.

 

[CJ6]

It can only be one of 3 things pockets, pressure, primers.

 

[searcher]

Those Tula primers fit tight. I have fired over 30,000 of them and have never experienced what you did with the primer leakage. I'm guessing the load is either too hot for your barrel or there is another issue going on. If I were to place a bet, I'd be betting on the Tulas being one of the last to leak like that. I shoot both the .223 primers and the .223 "magnum" primers. No issues with either. I'd substitute the primer with that same load and see whether they still do that.

 

[Webster]

I have a pic of some brass where there appears to be gas leakage in the primer cup.

Once fired FC, hand primed with Sinclair tool. - So the pockets were acceptable. (I sort off the loose ones)

Tula Primers.

62 gr FMJ

N135 powder - 2700 fps out of a 20" Rem 700 (M855 goes like 3100 fps, so this isn't a hot load)

Any ideas? (The swipes were there from original firing - Airforce military traning ammo)

Primer flow is the standard Rem 700 bolt action/large firing pin hole deal.

I have a pic of some brass where there appears to be gas leakage in the primer cup.

Once fired FC, hand primed with Sinclair tool. - So the pockets were acceptable. (I sort off the loose ones)

Tula Primers.

62 gr FMJ

N135 powder - 2700 fps out of a 20" Rem 700 (M855 goes like 3100 fps, so this isn't a hot load)

Any ideas? (The swipes were there from original firing - Airforce military traning ammo)

Primer flow is the standard Rem 700 bolt action/large firing pin hole deal.

The ridge around the FP indent is larger than what I see on 2 my Rem 700 rifles. The edges are nice and round. Did you swage the pockets and maybe make the a little bigger in diameter. If the primers seat with a good firm pressure it would indicate a good cup fit to the pocket. Do you have excessive clearance when checking with a bump gauge?

 

[kilowatt41]

I use a Sinclair neck insert gauge to measure my chamber for overall case length. This gives me a maximum oal for my brass and chamber.
If your cases are too long you could be crimping your brass, that would explain the pressure with a quote safe load.

 

[markm87]

I double checked the brass in a Dillon head space gauge, and it passed the OAL and Headspace limits.

The leakage appears in both a Rem 700 and a 5.56 chambered AR. I may shoot 20 with another brass flavor just for the heck of it... LC or some PMC.

 

[fkimble@charter.net]

Have you compared the case volume of those FC cases compared to others? The across the course shooters tend to avoid FC cases or just use them once for shortline practice loads.

Frank

 

[Nowhere Man]

Pushing the bullet into the lands can also cause over pressure.

 

[distinguished]

Federal is well known for loose/bad primer pockets. I had issues even with once fired federal match! I stopped using Federal brass a long time ago and never had a problem since.

 

[markm87]

Have you compared the case volume of those FC cases compared to others? The across the course shooters tend to avoid FC cases or just use them once for shortline practice loads.

Frank

I've not yet. I could do a quick weight comparison to get a rough idea.

 

[markm87]

Federal is well known for loose/bad primer pockets. I had issues even with once fired federal match! I stopped using Federal brass a long time ago and never had a problem since.

For sure. This brass is not as stout as LC, but I got 4k pieces I'd like to get one firing from.

 

[jk80]

Wasn't there a issue with certain lots of winchester primers a few years back or I'm i imagining things. I know I had problem with some shotgun primer 6 or 8 years ago. Misfires and a few leaking. Cheddite was bad for a while too.

 

[Doom]

Wasn't there a issue with certain lots of winchester primers a few years back or I'm i imagining things. I know I had problem with some shotgun primer 6 or 8 years ago. Misfires and a few leaking. Cheddite was bad for a while too.

Yes there was. Back around 2010-2013 if memory serves me right.

 

[markm87]

I ran a little experiment this Saturday. Loaded the exact same components and load (including the Tula Primers) in the FC and some LC brass.

LC brass (right) had no issues in 3 different guns (2 ARs and a bolt gun) and the FC continues to show leakage (left). The combo of the Tula and FC brass seems to be the issue.

(again.. the primer flow is in the Rem 700 which gives that on every load, the primers with no flow were fired in an AR15)

 

[jsn]

Your first photo IMO clearly showed a higher level of leakage in brass where the case head showed bolt face setback. Can't see this as well in the second photo.

Which Tula primer are you shooting? Numerous posts on this forum state that experience shows the KVB223 are softer than the KVB556.

Maybe the issue is a combination of softer FC brass with this primer?

 

[DShortt]

Based entirely on what I see in the images, you've got a reason to consider bushing the firing pin hole in your bolt on the Rem 700, but that isn't what is causing the leakage.
You can go to LC brass and the issue goes away. You didn't try Federal brass with different primers so it's not a complete experiment. But given what you've tried thus far, I'd tend to give the 'stink eye' to the Federal brass.

 

[Savagenut71]

When you knock the primers out, is there a hole in the cup like here?

Were primers crimped in & pockets swaged?
Gauge link

There are go/no gauges to measure primer pockets.

View attachment 1599779

Actually there are go/no go gauges for primer pockets. Kiff makes them at PTG

 

[DShortt]

Punch out the primers on the rounds with soot and examine them and the primer pockets with a critical eye. Seat a new primer in the same exact cases and note the required effort.
The answer is here. You've just overlooked it.