Primers with a hole in them?

[MikeS]

Hi All.

I was at the range today, firing a new to me Tanfoglio GT41 chambered in 41AE (Action Express), and noticed some odd things. First off, I was shooting cast boolit loads, a 170gr SAECO #416 (looks like an H&G #68 scaled down to 41 cal) with 5.2gr of Unique. On some of the cases it looks like the firing pin actually punched a hole in the primer! At first I thought maybe the firing pin was rough, but looking at the other cases they have a nicely rounded hit where the firing pin struck the primer. The gun shot fairly accurately, except for some random fliers, it's possible that the fliers were the shots were the primer was punctured, but I don't know for sure. I also noticed that the last round or 2 in the magazine had a tendency to stovepipe, and one piece of brass actually got so mangled that I had to throw it away (at over $1.00/ea for brass, that hurt!). Also the primers were flattened more than I'm used to when shooting 45ACP, but I'm not sure if it was excessive, or if it's normal for loads in some of the higher pressure cartridges to make primers flatter than from low pressure rounds like the 45ACP.

I slugged the bore on the GT41, and it came out around .409 to .4095, so I ordered a .411 sizing die from Lathesmith, but didn't have the die when I loaded the cartridges, so I loaded them as cast (I pan lubed them), and as cast they were .415, but the cartridges fit into the chamber without any problems (but I did have a couple that didn't go all the way into battery, so I had to push the slide a bit to get it fully closed). Would shooting boolits that are .005 - .006 larger than the bore cause the pressure to get much higher? Is the punched out primers a sign of excessive pressure?

The primers I was using are the Tula large pistol primers, and the person I went shooting with (another forum member) suggested that I should try loading some with CCI primers (or other American made primers) to see if it makes a difference. I only have 49 cases, so I loaded 25 of them with the Tula primers, and when I get some other primers (I think I'm going to get some CCI primers later today) I'll load the rest with the same load, same boolit, with the primer being the only difference between them. And I almost forgot, I got the sizing die in the mail yesterday (Thursday), so I sized all the boolits to .411, perhaps that will make a difference.

Anyone have any tips, or ideas on why the primers got punched out on some, and not on others? I didn't weigh each load, I use a Lyman Accumeasure, and it seems to throw charges pretty well.

[Chicken Thief]

There is a big difference in the hardnes of the primer material from different manufactors.
As far as i can remember Federal and Winchester are hard and will eleminate deep punching and "set back"/flattening.

Cant be pressure because i ran 5.2gr with a Lee 185gr boolit and only gor @24000spi.

[Revolver]

I don't have an answer but I ended up with some spent 7mm mauser brass that I got in a bundle, some of them had holes in the primers too. They were reloads that the previous owner made & shot.

Additionally, I have a Tanfoglio 45ACP (The full size metal frame model) and I love it. It shoots great and is easy to clean. I must confess I haven't shot it in awhile, now I'm gonna dig it out and use it! Thanks for the reminder.

As for your problem, maybe it's the primers? Thin brass combined with a stiff punch from the firing pin?

[captaint]

The only time I have pierced primers was some 6BR ammo I loaded years ago with J work bullets. The load was too hot, never used that powder charge again. And a shame it was, because it was the most accurate ammo I ever loaded for my XP100.

But again, in that case it was the "too hot" condition that caused the pierced primers. I don't know much about the 41AE, I would think that .005 to .006 over groove diameter in a higher velocity cartridge could cause your issue. Hope this helps. enjoy Mike

[skeet1]

I have had problems with Remington Factory 9mm ammo in my Blackhawk .357/9mm convertible. Primers had holes in the very center of the indent and leaked. This does not occur with other brands and I believe the Remington primers have a very soft or thin cup. My Ruger also may have a firing pin that protrudes a little more that normal.

Ken

[RACWIN375]

sound like pressure look at the case head does it look a little funny like it was pushed into the bolt??? what has happened is the case was pushed back onto the firing pin when it was still sticking out of the bolt before the spring pulled it back or stopped pushing the firing pin

I had a 22 hornet with a bad head space and it would do that and the amount of powder didn't matter

Rick

:Fire:

[Chicken Thief]

sound like pressure look at the case head does it look a little funny like it was pushed into the bolt??? what has happened is the case was pushed back onto the firing pin when it was still sticking out of the bolt before the spring pulled it back or stopped pushing the firing pin

I had a 22 hornet with a bad head space and it would do that and the amount of powder didn't matter

Rick

:Fire:

I ran the numbers and it is not high pressure!

[Rocky Raab]

Whatever the cause, if you shoot many loads that way, you will probably erode the firing pin tip - and then you will pierce most or all primers after that.

[Moonie]

I'm with Rocky Raab, an issue with your firing pin tip can and will cause this. It isn't always due to high pressure.

[chboats]

Check the head space. Excessive head space can show its self like high pressure. Firing pin drives the round forward and the primer backs out. The pressure will drive the case back and flatten the primer and sometimes pierce it.

Carl

[RevGeo]

I ran the numbers and it is not high pressure!

What is high pressure in one gun may not be in another. Pierced primers are nothing to fool with and the cause should be found. Any time the integrity of the cartridge/chamber is compromised a problem exists. Whether it is a primer problem, a hot load problem, a headspace problem or whatever, it needs to be addressed. The fact that the primers were flattened more than normal might indicate a pressure problem, as would pierced primers. The .45ACP headspaces on the case mouth, so perhaps OAL might be checked.
The plan of trying different primers, reducing the load and sizing the bullet (one step at a time) seems pretty smart to me.

[fredj338]

If there are no other signs of over pressure, then it could be yor firing pin has a rather sharp point. A very light stoning, just to blunt it a bit, could solve the problem. If it happened once, anomoly, if it happens often, start checking the gun. I doubt your load is that over pressure, but anything is possible.

[bld451]

Tht can happen for several reasons. Look at the condition of the firing pin (should be round and smooth) , and how it fits in the pin hole in the bolt face (no more than about .005" clearance). Also if you can check protrusion, that would be good (assemble the gun without the barrel, and with the slide in the closed position, and the hammer in the down position, measure with a dial caliper "tail" through the muzzle end or looking across feeler gauges from the top). Should be between .035" and .055" I suspect you'd see some serious problems if it were just pressure. Probably take more than 40,000 PSI or so to do that with a pin in good shape that fits the breech properly. If you notice the headstamp area of your brass "imprinting" the boltface features on it and loose primers, you're in excess of 70,000 PSI. Not likely if your gun still works.

At any rate, do what it takes to remedy that, including a gunsmith visit, if necessary. It will cause malfunctions and a locked up firing pin at a minimum--I'll leave you to imagine the worst.

Good luck. Let us know how it works out.

[RACWIN375]

Check the head space. Excessive head space can show its self like high pressure. Firing pin drives the round forward and the primer backs out. The pressure will drive the case back and flatten the primer and sometimes pierce it.

Carl

that what I was trying to say

in running your numbers did you factor in that something is wrong with the gun????

Rick

[wallenba]

Maybe the primer cups vary in height and material thickness. Maybe the primer pockets were not uniform depth, making them closer to the pin, thus puncturing. Otherwise, I think headspace.

[bld451]

Upon reading your OP again, you said you had to assist the slide on a few shots. Have you looked into why? Did your boolits engrave the rifling, or did the leading edge of the boolit hit the end of the chamber, or was it that the rounds were too fat? It could be that on those rounds, you didn't have any room for the case neck to expand to let out the bullet. That and a .005" over bore condition could spike your pressure significantly.

[MikeS]

I'm pretty sure that I had to assist the slide going into battery because of the boolits being on the fat side. It's also possible that there wasn't room for the case neck to expand. I've fixed those problems (I think) by sizing the boolits to .411 now that I have a sizing die. I'm going to get some different primers to try as well. Being that I'll be changing 2 things at once I loaded up 25 rounds using the same primers, so on those there will be only one change (the boolits being sized). This should help me eliminate some things as problems. I figure if I have no more punctured primers at all, then it was the sizing. If I still get punctured primers on the ones primed with Tula primers, but not with the other primers, then the primer was the problem. If I still get punctured primers with both brands of primers, then I need to do more investigation to try and find the problem.

[scb]

I'm pretty sure that I had to assist the slide going into battery because of the boolits being on the fat side. It's also possible that there wasn't room for the case neck to expand.


I ran the numbers and it is not high pressure!

Then again maybe it was. Or when you "ran the numbers" did you account for an oversized bullet or maybe a tight chamber or maybe thicker than normal brass or...........?

[MikeS]

Ok, I loaded another 49 rounds, half with Tula primers, half with CCI primers. I'm going to try and get to the range tomorrow, and see how they shoot.