Pressure signs with Bullseye in 45

I have been loading 4.0grs of bullseye under a Zero 185gr swchp for years.  I did not notice any problems until I had a malfunction with my bullseye gun at a match with the firing pin sticking out of the breech and would not return on its own. The breechface was peened right under the firing pin hole to the point at which it pushed metal towards the hole and started to cause malfunctions.  It has had the slide replaced and the problem continues.  I use federal primers which show the over pressure or "spike"  by flattening and filling the radius of the brass at the priming pocket.   My load consists of mixed brass, 4.0 Bullseye, federal primer, 185gr swchp seated at about 1.210 oal or about .920 case head to wadcutter edge.  I've tried about every kind of variation of primer and powder lots that I have trying to find the problem. I have currently changed to 4.2 WST and winchester primers to try and alleviate the problem.   Any insight would be greatly appreciated.

Workinman wrote:I have been loading 4.0grs of bullseye under a Zero 185gr swchp for years.  I did not notice any problems until I had a malfunction with my bullseye gun at a match with the firing pin sticking out of the breech and would not return on its own. The breechface was peened right under the firing pin hole to the point at which it pushed metal towards the hole and started to cause malfunctions.  It has had the slide replaced and the problem continues.  I use federal primers which show the over pressure or "spike"  by flattening and filling the radius of the brass at the priming pocket.   My load consists of mixed brass, 4.0 Bullseye, federal primer, 185gr swchp seated at about 1.210 oal or about .920 case head to wadcutter edge.  I've tried about every kind of variation of primer and powder lots that I have trying to find the problem. I have currently changed to 4.2 WST and winchester primers to try and alleviate the problem.   Any insight would be greatly appreciated.

Your issues are a mystery to me.  I also use 4.0gr of Bullseye under a Star 185gr lswhp with Federal 150 primers and mixed brass.  I have more than 200,000 rounds downrange with this load without any such symptom you describe.
I'm not going to speculate about potential causes and will leave that to the knowledgeable gunsmiths on this forum.

Mike

I shoot 4.0 BE 200 as break in load for all my pistol builds. I consider it a medium level charge in the bullseye realms.

What is your barrels headspace (measure from hood to front of chamber), brand (if Kart was chamber finish reamed)?

Have never seen a primer flatten from that charge. I wonder if something was stuck in your case before you loaded it?
Jon

All the bullseye loads with federal primers are flattened.  It's a KKM barrel with headspace of. 899

Ok thanks. Definitely finish reamed if a kkm.

I haven't used Federal primers in a while. I just looked at a fired case that had 4.0 BE and CCI primer. Still has rounded edges. I wonder if your Federal primer cups are thin?
Jon

Tried a couple of different lots of federal primers and they still show pressure.  Winchester primers show less, but the breechface peening is really what I'm concerned about.  Had never happened before in any other of my 1911s. Also measured the cup thickness on the sides and show 0.014, same as the winchester primers.   Quite frustrating

Are you saying your getting circular depression at primer location on breech face?
What brand slide? Some are softer than others on breech face.

And, OP said slide replaced and problem continued.

What are you using for a scale, and have you checked the calibration?

Sent you a pm Jon

Old slide brand?
New slide brand? Is it new or used replacement?

I use an Fx-120i balance and check calibration recently.  Gtg.

New slide brand.

Presuming that what you really have is Bullseye powder and that it hasn’t been compromised, I seriously doubt that over pressure is the problem.  Federal primers for decades have been thinner or softer than others but even still these loads shouldn’t give too much trouble.  I’d look at the flash hole size in the case.  It should be .080 or so.  Sometimes they get bigger/reamed out for ?? reasons.  If all that is normal, then I’d change powder to WST or a known batch of bullseye.  Then I’d look at different primers. Either CCI or Winchester.

So far, that is the current solution Wobbley
WST and  Winchester primers

I've seen radically flattened primers in a 308 with a mild load. Brass was sized ... over sized ... and the shoulder pushed back so the case head was held away from the bolt by the ejector spring. Primer backs out and flares, case gets pushed back over it.

here's a closeup pic of a federal compared to a winchester

Have you shot other people's ammo to verify that the same thing happens? What about factory ammo?

Dave

I have shot other ammo and the problem isn't there.  The pic above are both fired from the same gun.

So the primer on the left is your reload, and the primer on the right is someone else's? You're saying other people's ammo runs without showing pressure signs?

Or the primer on the right is your reload, but with a Winchester primer? 

Also, how old is the brass? Can you measure the brass length? 

Dave

Both primers  shot out of the same gun. The winchester was using 4.2 WST.  I tried a friend's load with clays and measured the primers shot out of his gun and mine. Measured the same diameter at the base of the cup. When I started this "investigation", I sorted my mixed brass by length to see if it was a headspace issue.  Same result. So far I'm showing my bullseye load the problem.  Loaded with a different lot of bullseye and same effect. On another note, I do case lube my brass before loading, possible issue?

Have you tried a different lot of BE powder? Did you open the suspect powder new?
Jon

Tried different lots and both were new. 

My next thought is to chrono your loads. Verify velocity is normal target range. Could be something wrong with your scale. Do you a have a simple beam scale you can check it against?

Dave

Yes. Checked on another digital scale and my beam scale.  All gtg