My First Blown Primer Wtf Happened?

[911rat]

I'm hoping someone can help me figure out what happened to me today.

 

I just replaced all the springs in my Glock 17 (Ok I lost a lot of you at Glock) and took it out to test fire it for function. The gun and shooter were doing really well. I put it down to cool while I practiced with my carry gun, a compact .45. I figured I'd finish off the rest of my 9mm ammo and on the first round the recoil felt funny, meaning there really wasn't any. I thought wow, what a difference in recoil until I noticed the slide had only moved about 1/8" after firing. The slide was jammed in place so I had to disassemble the gun in order to unlock it. A fired case with a blown primer was firmly jammed in the chamber.

 

I was shooting my own reloads. I load 9mm in lots of 500, checking powder weights constantly, recipe is 4.9 gr 231 with a 115 gr bullet. It chronographs at about 1150 fps. This was my last box of 50. The case was a WCC 92 Mil case.

 

I had put about 50 rounds through the gun before this happened and it was clean when I started.

 

I'm thinking that the problem was;

 

1. oversized flash hole or primer pocket

 

2. the bullet jammed in deeper when the round was chambered

 

3. Crud in the chamber contributed to high pressure.

 

4. somehow too much powder got into the case, I think it's unlikely because I load with a single stage press and check my powder weights thrown by the measure often.

 

5. There was some other problem with the case or a dirty chamber allowed the gun to fire out of battery, the case was fully seated when I took the gun apart though.

 

the case appears to exhibit some high pressure signs but I can't quite figure out what could have gone wrong. Perhaps I'm just not thinking clearly yet.

 

BTW both the shooter and the gun are fine, though I haven't stripped the gun yet, especially the striker assembly, to check for damage.

[ShooterTom]

The bullets you were using were they lead? I have heard Glocks can't handle lead Bullets and can result in high pressure.

I thought I had an article saved but I don't seem to be able to find it.

 

Tom

[karlunity]

I think that you covered most of the bases.

The only thing I would add is to check the firing pin.

If that is ok, since you have used this load often without a problem, don't worry about it at the range, but if this is your "carry" gun, I would stick to factory loads.

It would be very "embarrassing" to have a jam in a self-defense situation.

 

Karl

[AzRednek]

Rat as long as I have been cruising firearms related groups I've read of all kinds of problems with Glocks and reloads. Lead slugs being a paticular source of problems. Wish I could offer some real advice but you might search for a Glock newsgroup.

[911rat]

After looking at the case and thinking on it for a while here's my best guess.

 

It was a FMJ bullet. Fouling shouldn't have been a problem. Case has a bulge at the head. An unfired case inserted into the barrel looks as if it should be impossible to bulge quite that far.

 

This was the first round from the magazine. Possibly the slide didn't lock completely into battery.

 

I've just read that when you replace the striker spring in a Glock you must also replace the mainspring because they work together. I replaced the striker spring but used the mainspring that was in it (only had a couple hundred rounds on it).

 

Did a complete strip of the slide. All the parts look brand new. I installed a new mainspring.

 

I had thought about selling both my 9mms and buying a Browning HP. Problem is that I like the Glock. Now I'm rethinking it.

[Clark]

I have done a hundred work ups in 9mm that resulted in the same primer falling out and guppie belly bulge.

I have done the same in 25acp, 32acp, 7.62x25mm, 380, 9x23mm, 40sw, 10mm, and 45acp.

 

You had too much pressure.

That can be caused by a number of things or combinations:

too much powder

wrong powder

bullet jammed into lands

bullet pinched by brass and chamber

fouled throat

bore obstruction

switching to magnum primer

 

The case failure you experienced is not too dangerous, except in a CZ52 the chamber can fail.

But if you continue to add more powder the primer will pierce, the guppie belly will open into a hole, and the case head will blow off.

When the case head blows off the extractor can exit stage right at lethal velocities.

[Doble Troble]

The light recoil followed by failure makes me think that you might have had a squib. This may have put a bullet in the barrel which would have been the bore obstruction that Clark has pointed-out can cause these failures.