Two seperated case heads in 3 weeks!

[taco101]

3 weeks ago, about 1/2 way through a match I was shooting along and heard a shot that was "different". The mag shot out, and my left hand stung pretty good. We found the case and it was blown out right where the stock G-35 barrel is unsupported.

Kinda freaked me a bit. But the gun was ok and functioned just fine. I shot the rest of that match and another. Then yesterday, with a clean bore(my 6th shot of the match) that strange pop happened again. This time it KO's the extractor. (had to pirate one off of my G-23 carry gun to finish the match)

I have quite a few rounds down range since I got the gun last October. Haven't had any problems up untill 3 weeks ago. Nothing has changed with the rounds I'm shooting. (200g on top of 3.8g Solo1000)

I ordered a Storm Lake barrel.

Do ya'll think that might stop the problem?

[steel1212]

3 weeks ago, about 1/2 way through a match I was shooting along and heard a shot that was "different". The mag shot out, and my left hand stung pretty good. We found the case and it was blown out right where the stock G-35 barrel is unsupported.

Kinda freaked me a bit. But the gun was ok and functioned just fine. I shot the rest of that match and another. Then yesterday, with a clean bore(my 6th shot of the match) that strange pop happened again. This time it KO's the extractor. (had to pirate one off of my G-23 carry gun to finish the match)

I have quite a few rounds down range since I got the gun last October. Haven't had any problems up untill 3 weeks ago. Nothing has changed with the rounds I'm shooting. (200g on top of 3.8g Solo1000)

I ordered a Storm Lake barrel.

Do ya'll think that might stop the problem?

How many reloads on your brass? If they are all being shot through your unsupported barrel, then resized, the shot again, that resizer its doing work on the brass to get it back in shape.

[taco101]

How many reloads on your brass?

Not sure. Probably 3 or 4.

[SA Friday]

The only time I've seen this happen before was actually in a G34, 9mm. The shooter was using N310, 147gr Zeros, and Fed cases that had previously been shot out of SMG, we suspect an MP-5.

He culled the Fed cases out of his ammo and everything was GTG.

There are a few things that could be causing this. A combo of bad brass and high pressured powder is the one I've seen before. Did you save the blown out brass? Are there any characteristics similar about them, brand, marks on the case like a Schueman barrel but more apparent? Could be you got some really shredded stuff mixed in with other brass.

Another cause could be overpressure from bullet set-back. 200gr bullet takes up a lot of case for glock length loads. If you get a little set-back, you could be getting enough overpressure to blow out a case.

[dirty whiteboy]

Brass.

What was the head stamp on the ones that blew off.

Do not use PMC brass.

[Flexmoney]

Do ya'll think that might stop the problem?

Nope.

It might mask it.

- You may have exceptionally weak brass (used too many times, or old "F C" or PMC brass)

- You loads are causing over-pressure.

[taco101]

Time to go through the brass bucket I guess.

[mlmiller1]

Todd,

I know that is a very soft shooting load but loading 200s in a glock is right on the edge of bad things happening. Then you guys are using that fast powder which is just really pushing the envelope further. I didn't realize you were loading 200s. I tried loading a few 200s & wound up selling all of them I didn't load. 1975 of 2000. It just made me uneasy. Be careful my friend.

The gun is doing exactly what it is supposed to do when the case head blows. The pressure is going mostly out the bottom, saving both your hands & the gun from major damage. If you change things up very much, you may not get any better results, perhaps worse ones.

Have you tried 180s? The pressure is lots lower & the margin for safety is higher.

See ya

Mark

[mike4045]

I traced any problems I had back to bad cases. I never got he 200 gr. bullets to feed reliably. Saved them for an STI. I got rid of all FC marked cases. I stick with to winchester and remington for my Glocks. I no longer picked brass out of my Glock. I buy once fired brass and use it in practice and then leave it on the ground at a match.

Mike

[Guy Neill]

Since the cases have been reloaded repeatedly, they have work hardened to some extent. Depending on how hard they were begin with, they may not be holding the bullet as well, allowing it to telescope into the case while feeding, thereby raising pressures. Maybe.

Guy

[Tom D]

Do ya'll think that might stop the problem?

Short answer, no.

If you look at the reloading manuel, Solo 1000 is not recomened in any handgun smaller than a 45 acp. I was told about a load for the 40 and had the same results. In about 150 rounds I had 2 casehead seperations. I went back to Vit 340, and have not had any problems since then. I was using 180 Gr bullets loaded long for a STI. A lot of shooters had similar problems back around 2000 using 220's and Clays. It is just too fast for that heavy a bullet. A case head problem cost Todd Jerret the Nationals in 1998? or 1999? (it think) at PASA on the last stage. He was using 220's with Clays

Later

Tom

[Braxton1]

I have used 200s in a Glock with a factory barrel, but I only used slow powders and loaded to the max OAL that I could fit in the mag (the exact number escapes me now, as I don't have my reloading log with me). Never had a problem with it.

I had a similar blow-out a couple of months ago with 180s. I was using the U-Die but quit using it because it was slowing down the 1050. That was a big mistake, as we suspected bullet set-back.

There was a test done a few years ago by a certain manufacturer of 40 caliber pistols. They shortened the rounds and found that .030 set-back could double the pressures at a certain point.