Pressure signs with Bullseye in 45

First topic message reminder :

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.

Try your bullseye load with Winchester primers see if it’s truly powder or primers.  Federal primers are notoriously soft.

Hiya,

Couple things, first, Federal primers are the preferred primers for modified revolver shooters as they are considered “softer” and more reliable with the reduced mainspring tension for a lighter double action pull and in my experience they do tend to “show pressure” before other brands do. Second, your picture of the fired primers really looks like they are backing out due to either lose primer pockets or excessive crimp removal from either swedging with a tool or chamfering with a cutter. (The lighter band on the OD looks like about 50% engagement in the pocket) I used to see primers like yours in service rifle with reloaded 30-06 brass that the person didn’t have a swedge tool and used a case chamfer tool to remove the primer crimp on military cases. The primers would look flattened from high pressure but in fact they simply swelled to fill the chamfer.

How many reloads have your cases seen and are the pockets chamfered?
IIRC I used to run 5.5, maybe more of bullseye with a 200 to make major in IPSC so I doubt your close to high pressures with anything in the 4’s with a 185.

Try 4.0 BE loaded by a friend! Give them your primers for the reloads.
Take yourself out of the equation. 
Jon

Having loaded many rounds of .45 ACP with Bullseye, I doubt that you are getting high pressures. I've very recently been loading many thousands of 200 gr. lead coated SWC bullets with 4.6 grains of Bullseye and am not getting high pressure signs with Winchester primers. It seems like you've narrowed the issue to the Federal Large Pistol Primers.

I think WesG is on the right path. Headspace can  cause the primer to backout and then get flattened


Did we ever figure out how the FP hole got peened?

No not yet.  Will be testing more on Thursday.

The barrels headspace has gotten shorter because of lead shavings build up in the front of the chamber. 

You started with almost a minimum SAAMI headspace. Add using new brass that may be at maximum trim length, adds to the problem.

https://www.thehighroad.org/index.php?media/primer-swipe.2998/full

Concur with most all other comments. I would only add:

Check/clean barrel. In my KKM barrel I get a small amount of leading when set at .920. At .930 I do not when loading Zero 185 LSWCHP bullets.

I load 4.1 WST with same bullet. It is a moderately soft load.

Unless I misread, you indicated a firing pin hang up. Remove slide, remove firing pin, clean firing pin, FP spring and FP cavity, Maybe a new FP spring wouldn't hurt.

What do bullet holes look like and how is the accuracy compared to before?

How much does the loaded round weigh?

Keep us updated on this one. My bet is something simple, being overlooked, but who knows?

I think we are missing something. Didn't he say his firing pin was hanging up and the breach face was peening the firing pin hole shut?

Yes that is what was happening with the firing pin hole. The peening would start to close the hole causing the firing pin issue.  As far as cleaning, I've used a brass pick to check for lead on the edge of the front chamber and I only see carbon buildup at  most if at all.  My short line brass i use is once to several firing mixed brass.  Still undergoing testing.  Will update

Have you done a plunk test with your current ammo  ??

Should not be longer.than the breach end of the barrel hood

Might be a good test to remove your slide drop a live round in the chamber and lock the barrel with the bushing in place
 Take a picture of the case and extractor from the bottom of the slide

Btw.does every round exhibit the backed out primer ?  Are you sure the firing pin is now functioning correctly ?

How do you peen a firing pin hole with a brass case? (Not being sarcastic, I’m genuinely confused. Dumb question, are you cleaning with steel pins? The case lube makes me say “hmmm…” because case expansion against the chamber wall is important.

Sorry this is happening, but it’s a heck of a mystery. I like the idea of trying someone else’s reloads.

More than likely the case rim is striking the firing pin hole at 6 o'clock and peening the edge over as it slides by. It's possible that the slide was not hardened correctly and the breech face is soft, allowing this to happen. Softer slides do show signs of the case bottom eroding away the breech face surface on high mileage pistols. Also see jhp erosion on feed ramps of SS lowers.
Jon

Thanks Jon I would never have suspected that a brass case could peen a steel breech face.

Apologies to the OP for me being Inspector Clouseau (the trait comes from being a lawyer with a science background in a technical / engineering legal field ) but what I notice is:

1. All is good till one day the firing pin is sticking due to a peened over breech face FP hole. What changed to cause that?  Could something have changed in the slide or components to cause the peening?  If the gun had been fine for many many rounds, something might be amiss with the frame side of the equation.

2. You say that you didn’t have any problems until the point you noticed the stuck FP / breech face hole peening at 6 o’clock.  When you say “problems” do you mean peening of the FP hole, flattened primers, or both?

3.  Changed the slide and the problem continues.  Which problem? FP peening, flattened primers, or both?

As an experiment, can you shoot your reloads in another gun and compare?

Sorry to be intrigued by your issues.  I don’t mean to be a drive-by, rubbernecking gawker. 

Rod

Jon Eulette wrote: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

I sent an email to a friend to find the actual primer hardness data we collected about 10 years ago. My friend had a problem with his 70s National Match (Kart Barrel) and Federal primers, with the firing pin getting hung in the primer. It almost looked like the primer had striker drag as you would see on a striker-fired gun. On some of the primers, you could see where the firing pin went through the surface of the Federal primer. My friend, being an engineer built a jig and used a transducer to measure how my force it took to penetrate the primer material. The federal primers were considerably softer compared to CCI and Winchester primers.

In part of the process, we removed the firing pins from all of our 1911s and measured their length, maybe the firing pin in his Colt was too long. The firing pin was in spec, but he installed one that was about .001 shorter than the Colt. He put an extra power spring in, but the same result. He contacted Federal, Federal had him take the primers to Perry's Gun Shop and trade them out for a different lot. One interesting thing, being the engineer he is, he ordered a Titanium firing pin and loaded 10 rounds from the old partial tray of Federal primers, there was no firing penetration or drag marks of the primer. He kept the Titanium primer in the gun until he went through the new Federal primers, then switched back out to the steel as the Titanium had light strikes on the harder primers.

Have you tried verifying the powder charges with a different method.. 

take a primed case, toss in a weighed charge, then weigh THAT on a scale..

Also, have you checked bullet diameter or weight.. ive found 165 grain bullets in 150 grain boxes before for rifle.

Check scale with test weights.



 Long trim length/range brass.  

Seat dies can shave lead. Lead ends up in chamber. Lead build up in chamber- Head space on case mouth short.

Workinman wrote: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?

yes and no, on the case lube. One should be cleaning the brass off.. 

However in a cheerful note, the british governemnt had a test for the service rifle in .303.  They would oil the cartridge case, it increased chamber pressure, and rearward thrust on the bolt by about 40%.  

Now on YOUR ammunition... have you tried OTHER primers?  Can easily be a bad batch of primer you have.

As to answer a few questions as of late, I've checked chamber length/cleanliness, no lead shaving, verified scale and load weight, tried different primer and powder lots. Still testing, but haven't had much time recently. Thank you gentlemen for your interest and your input.