.223 primer blowback/gas leakage.

[markm87]

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.

 

[jelenko]

Was the original primer pocket crimped? If so, how was the crimp removed?

 

[243winxb]

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.

 

[Jeff Porter]

I ruined a bolt face using Tula primers that blew out at the radius like that.

 

[Coyotefurharvester]

Try some new commercial brass, see if you still have this NOT good situation. Do you have your sizing die setting set correctly? Excessive headspace. NOT good for maintaining primer seal.

 

[markm87]

Primers were originally crimped. Man... I hope the Tulas aren't a problem, because I have at least 5k of them.

I'll definitely try some LC and other flavors of brass too.

 

[jelenko]

On Tula primers. When they were still being imported into the US, they were very popular with 'cross the course' shooters. I'd estimate several hundred K were used. There were no reports of Tula's leaking around the edges.

ETA: Just saw Jeff Porter's report in post #4 above. There's at least one report of Tula's leaking around the edge.
My personal experience. In the time, I used ~ 20K of Tula/Wolf primers with no leaks.

 

[CJ6]

I've never had a problem with Tula SRPMs. I've shot over 115,000 of them.

 

[markm87]

That's good to hear. I was hoping it's just the weak FC brass that's known for thinner case webs.

I got huge pile of the brass so I want to iron out any bugs before cranking out a bunch of rounds.

 

[mmcu]

That's good to hear. I was hoping it's just the weak FC brass that's known for thinner case webs.

I wouldn't jump to that conclusion. I've shot thousands of FC 03 / 05 / 07 and FC 223 brass without primer leakage issues.

Is it the best brass? No, but I'd be looking at every aspect of your primer crimp cutting / swaging and gauging before assuming it's the brass.

Headspace has been already mentioned, but is worth bringing up again.

Just my $0.02 worth.

 

[243winxb]

weak FC brass that's known for thinner case webs

I remember when that was a thing, posted at AR15.COM. I took measutement of my FC brass & found i had thin webs.
Was never an issure for me.

cranking out a bunch of rounds.

Can turn into a lot of bullet pulling. Brass does not always age well.

A progressive press may produceca different shoulder bumps from each station.

 

[markm87]

I wouldn't jump to that conclusion. I've shot thousands of FC 03 / 05 / 07 and FC 223 brass without primer leakage issues.

Is it the best brass? No, but I'd be looking at every aspect of your primer crimp cutting / swaging and gauging before assuming it's the brass.

Headspace has been already mentioned, but is worth bringing up again.

Just my $0.02 worth.

Thanks. Yeah... nothing has changed in my loading process at all. Crimps are cut with the Hornady cutter than I've had for many years.

This brass is all once fired "03 FC" head stamped with various pressure signs on some of it. (obvious swipes)

I size on a single stage with a carbide Dillon die (Expander ball removed), then open the neck back with a separate neck expander die. I've not had headspace issues or case separation.

I'm repeating the load with a primer substitution this weekend. Not that the primer is the problem, but perhaps the combination of everything is the issue.

 

[markm87]

I subbed some Fed AR Match in on 10 rounds and saw no leakage. But a primer swap changes the characteristics of the load drastically.

I continue to see 2-3 out of 10 with some gas leaking on the original load.

 

[Mark611]

Did you clean the rifle just before shooting it? I had a similar problem years ago, but not with these primers.

 

[Bill K]

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.

maybe some weak cases and also you say it is not a hot load. It may be to hot a load, even if the book data says not, in Your Rifle. Try some lighter loads and see if stops.

 

[SeabeeKen]

I prefer swaging out crimps. It doesnt remove any brass from the case and exposes less of the primer as opposed to cutting a bevel in the case and exposing more of the primer radius. JMO

 

[dellet]

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.

A couple thoughts in general.

Lower velocity with a different load, yours vs M855, has nothing to do with safe pressure. Looking at data for N135 and 60-65 grain bullets, loads start topping out around 27-2800 in barrels 24-26” long. The M855 uses a different powder.

The “D” shaped extrusion on the edge of the brass where it flowed into the ejector hole, is a certain sign of high pressure. If that’s what your referring to as a swipe, it’s not. So the question is whether it was there before firing in your rifle is important.

If it was there from the previous firing, it may be your problem. That raised bump on the case head will not allow it to have full contact with the bolt face. Note that on every case head, the burn mark is at that same place. The more pronounced the bump on the case head, the more carbon flow there seems to be.

If that flow into the ejector hole happened firing in your rifle, the load is too hot for the brass, and/or your bolt face may not be square to the chamber when fired. Maybe a carbon build up in the chamber, something stuck to the bolt face. Lots of possibilities.

If the brass that you did not have problems with, does not have the mark where it flowed into the ejector hole, it’s probably your answer. Then the only question is what rifle did it happen in?

 

[old codger]

I have had the same problems with some Winchester LRP.

 

[markm87]

I noticed a few more of these yesterday on the same brass, but with 23.5 gr TAC and CCI #41 primers with 62 gr FMJBT W/C.

Much fewer and less obvious, but still happening a little bit.

 

[Brew2]

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.