hole in primers?

[Raptor77]

Rifle is AR-10/LR-308 and began life as a .308 with V-seven barrel and BCG. Replaced barrel with Criterion in 6.5 Creedmoor. A buddy gave me 40 once fired Federal brass that I loaded with Winchester WLR large rifle primers. No problem. Then I bought virgin Lapua brass and loaded with Federal 205 small rifle primers and get the holes like in the picture. Loads are mild/ not hot. Head space is good. I think it's the primers, but not sure what to do about it. Does someone make firing pins that are undersized? Could this possibly solve the problem. I have 3000 of these primers and would like to use them if possible.

 

[KZP]

Your photo isn't working. But they do make 'high pressure' bolts for gas guns. One feature is smaller firing pin. I use the JP high pressure bolt in my 308.

 

[FCS]

Pictures would be very helpful.
Port location?
Port size?
CAR or Rifle buffer?
Weight of buffer?

Load might be mild for a bolt gun but depending on burn rate, might actually be causing issues in a gas gun.
What powder, charge weight & bullet is being used in load?

 

[sawgunner2001]

Win LR primers suck. This is normal for them. They pierce at mild pressures. Exacerbated by an AR, but they pierce easily in bolt guns as well. I too, have several thousand of them collecting dust in my inventory. Sorry to be the bearer of bad news.

 

[357Max]

Win LR primers suck. This is normal for them. They pierce at mild pressures. Exacerbated by an AR, but they pierce easily in bolt guns as well. I too, have several thousand of them collecting dust in my inventory. Sorry to be the bearer of bad news.

Accept he said it's the Fed 205 sml rifle primers that are piercing.

As FCS said, OP needs to provide more details.

I've had this issue & in my case turned out to be a very very hot lot of XBR.

 

[Raptor77]

Win LR primers suck. This is normal for them. They pierce at mild pressures. Exacerbated by an AR, but they pierce easily in bolt guns as well. I too, have several thousand of them collecting dust in my inventory. Sorry to be the bearer of bad news.

Win primers aren't piercing. The Fed 205 primers are.

 

[BuildingConceptsllc]

OP, did you chrono these loads?

 

[Raptor77]

18" barrel
rifle length gas
adjustable block
10 oz A5 buffer w/ titanium BCG

123g ELD-Match
42.9g Staball 6.5
2680 fps
and

147g ELD-Match
41.3g Staball 6.5
2370-2392 fps

 

[sawgunner2001]

Win primers aren't piercing. The Fed 205 primers are.

Ah, forgive me. Was still on my first cup of coffee. Carry on, folks.

 

[XikoPlavi]

Just to try you can ream the primer pockets out to .125-.130. (Max depth for SRP) and set the primer deep.

Can you load the ammo and eject it easily

You sure your not jamming in the lands from not enough throat freebore?

 

[BuildingConceptsllc]

18" barrel
rifle length gas
adjustable block
10 oz A5 buffer w/ titanium BCG

123g ELD-Match
42.9g Staball 6.5
2680 fps
and

147g ELD-Match
41.3g Staball 6.5
2370-2392 fps

Yeah that's not all that hot for staball. Shouldn't be piercing them.

So there's no way you havr any issue with brass vs chamber?

 

[ma smith]

Maybe relevant

New Federal Gold Medal Match Primers for ARs « Daily Bulletin

Federal Ammunition has released a new type of small rifle match primer optimized for AR15s and similar semi-automatic rifles. The new Gold Medal® AR Match Primers, designated GM205MAR, have harder primer cups than the popular Federal 205M match primers. The harder cup is designed to perform...

bulletin.accurateshooter.com

 

[FCS]

18" barrel
rifle length gas
adjustable block
10 oz A5 buffer w/ titanium BCG

123g ELD-Match
42.9g Staball 6.5
2680 fps
and

147g ELD-Match
41.3g Staball 6.5
2370-2392 fps

What is FP diameter? What is diameter for FP in bolt face?

Any other powders available? StaBALL 6.5 is showing as a little slower burn rate than 4350s, Viht N-550, IMR4451 and I suspect the time-pressure curve is causing you issues.

Running suppressed or unsuppressed?

How much difference in powder charge between Hornady brass and Lapua brass?

 

[Raptor77]

What is FP diameter? What is diameter for FP in bolt face?

Any other powders available? StaBALL 6.5 is showing as a little slower burn rate than 4350s, Viht N-550, IMR4451 and I suspect the time-pressure curve is causing you issues.

Running suppressed or unsuppressed?

How much difference in powder charge between Hornady brass and Lapua brass?

Suppressed

 

[FCS]

High back pressure can?

How much difference between charge used in Hornady brass and charge used in Lapua brass?

Time - pressure curve combined with suppressor is biting you with StaBALL. Any other powders available?

 

[918v]

You’re using the wrong primers. Use 450’s /41’s or 7 1/2’s.

 

[FCS]

You’re using the wrong primers. Use 450’s /41’s or 7 1/2’s.

918v does have a good point.

I'd add GM205MAR to that list.

 

[357Max]

Could be a full grain or more difference between the Federal brass & Lapua. Federal most likely being on the + side.
I don't have any Fed Creedmoor brass on hand to measure.

Could also be a spicey lot of powder, Chrono will tell.

 

[BuildingConceptsllc]

View attachment 7889864

Rifle is AR-10/LR-308 and began life as a .308 with V-seven barrel and BCG. Replaced barrel with Criterion in 6.5 Creedmoor. A buddy gave me 40 once fired Federal brass that I loaded with Winchester WLR large rifle primers. No problem. Then I bought virgin Lapua brass and loaded with Federal 205 small rifle primers and get the holes like in the picture. Loads are mild/ not hot. Head space is good. I think it's the primers, but not sure what to do about it. Does someone make firing pins that are undersized? Could this possibly solve the problem. I have 3000 of these primers and would like to use them if possible.

Have you tried using a cci 450 or the #41's? Assuming your primers aren't actually defective, you could probably trade for them. I have a few boxes of the Large #34 and I think they are still semi available

 

[Raptor77]

918v does have a good point.

I'd add GM205MAR to that list.

Where are you guys finding primers? That’s all I could get

 

[918v]

Where are you guys finding primers? That’s all I could get

Buy whatever primers you can and then trade them for the ones you need.

 

[FCS]

There is that issue.....primers are not "easy" to source.

Any other powders available?

 

[Cascade Hemi]

Don't use SRP in your AR308.

 

[BuildingConceptsllc]

Where are you guys finding primers? That’s all I could get

You have to work at it, but they can be found. The powder in stock thread or if you really want em, do the discord thing. Target sports has had 5000 for $600 for a while but I know that's a lot of em

 

[Im2bent]

See post #2

 

[Raptor77]

You have to work at it, but they can be found. The powder in stock thread or if you really want em, do the discord thing. Target sports has had 5000 for $600 for a while but I know that's a lot of em

The ones I found were in Louisville and wouldn’t ship. I live in Ohio and had to go get them

 

[BuildingConceptsllc]

The ones I found were in Louisville and wouldn’t ship. I live in Ohio and had to go get them

If you monitor and watch the powderbin stock thread you should be able to get some. I checked and targetsportsusa.com still has the #41's but they don't have the LRP anymore. If you want to get less than 5000 then I'd just watch that thread here and just make sure when you get the notification, you go check and see if it's primers and if so, you jump on em right then. You will get em. Or try to trade some of what you have for some or some 450's. I think those are the same or close to the same cup as the mil ones. I've gone or am going to, using the 450 for all of my SRP instead of the BR just to simplify everything.

 

[Haney]

Loads look mild enough for either of the two brass case capacity wise . I suspect it's the small rifle primers not liking the speed(burn rate) of the Staball 6.5 , not so much the primers themselves . Good luck and keep us posted please .

 

[Raptor77]

Loads look mild enough for either of the two brass case capacity wise . I suspect it's the small rifle primers not liking the speed(burn rate) of the Staball 6.5 , not so much the primers themselves . Good luck and keep us posted please .

Will do

 

[357Max]

@Raptor77 - One more thing I'd question. You said Titanium carrier. You didn't say if this was a complete Titanium carrier from someone reputable like RCA??

Check firing pin protrusion. Should be +- .035. If you got north of .038 due to tolerance stacking of miss matched parts it could cause this.

 

[spife7980]

Your photo isn't working. But they do make 'high pressure' bolts for gas guns. One feature is smaller firing pin. I use the JP high pressure bolt in my 308.

See post #2

OP- Quit ignoring the right answer that was post #2.

You are using a .078-.082 firing pin while you should be using a “high pressure bolt” in ar lingo that has a .062 firing pin.

 

[Raptor77]

Thanks for all the info guys. I will be ordering the high pressure bolt. I will post results when I get it and get to the range.

 

[Scttschnd]

Little off topic rifle wise but I just started using Lapua SRP 6.5 cm cases, had a few FTF primers with the 450 tried 400's this weekend to test same load, pierced every primer. Ill be going back to my 450/7 1/2 / or 205MAR primers with this brass. In any gas rifle I stay away from soft cup primers.
My current comment is a bolt action. I did have issues with FTF using some old WIN LRP and CCC 200's but the 200's worked better in the LRP brass.

 

[918v]

Check your trigger function to make sure the sear is releasing the sticker without dragging.

 

[Raptor77]

JP Enterprises high pressure bolt now in rifle. Gas rings seem loose. Should I put the ring from the old bolt on it? Going to try to get to the range this afternoon to test it out

 

[KZP]

JP Enterprises high pressure bolt now in rifle. Gas rings seem loose. Should I put the ring from the old bolt on it? Going to try to get to the range this afternoon to test it out

That's normal. Their gas rings have less friction.

 

[Raptor77]

Thanks spife7980 and KZP. Just got back from the range. Ladder test done on two different bullets and no pierced primers. Seems to like the 147’s better than the 123’s