The Truth about Glocks and Cast

[Patricklaw]

Hmm, that barrel looks pretty caked up but I gotta ask, is a double charge a possibility?

I load on a Dillon 650 and I'm pretty sure the powder would be spilling over the top with a double charge. I'll say it would be next to impossible.

[robertbank]

I load on a Dillon 650 and I'm pretty sure the powder would be spilling over the top with a double charge. I'll say it would be next to impossible.

I agree, you can rule out a double charge. You would never get the bullet to seat.

Take Care

Bob

[FergusonTO35]

Sounds good, just thought I should ask.

[zubrato]

40 caliber is rather sensitive to pressure spikes, compared to other calibers.
Culprits can range from barrel leading increasing chamber pressure, fast burning powders, and too strong a crimp that interferes with headspacing. I have heard of a taper crimp just strong enough to jam into the throat and cause KB's with jacketed bullets.
I'd also have a look at your case neck tension that may be appropriate with correctly sized lead bullets, but weak with undersized cast. 40's are again very sensitive to pressure spikes and the force of slamming certain bullet profiles into the feed ramp could seat the bullet just deep enough to be dangerous.
Could be a combo of the above, glad to hear you're alright and not missing fingers.
Oddly for all the flak the glocks catch for KB's the shooters are usually stunned but rarely hurt, where I've seen pictures of 1911 KB injury that were more severe from metal fragments.



Sent from my iPhone using Tapatalk

[FergusonTO35]

Patricklaw, I think I would stick with those Lee slugs you were having such good success with from now on!

[Catshooter]

I have seen that odd sort of case failure before. It was in once (and I do mean once) fired S&B brass. I'm positive it wasn't over loaded. Can you tell the brass brand?


Cat

[yondering]

I have seen that odd sort of case failure before. It was in once (and I do mean once) fired S&B brass. I'm positive it wasn't over loaded. Can you tell the brass brand?


Cat

Not really an "odd sort of failure"; that's exactly what happens with excess pressure and an unsupported chamber. It's very easy to duplicate (if you were so inclined) with any brand of brass you might want to try.

That severe leading can certainly raise pressure to the point that it's a problem. Of course, what nobody talks about is that the same load probably would have leaded just as badly in a conventionally rifled barrel too. The takeaway here should not be "don't shoot lead in Glock barrels", it should be "don't shoot a bunch of rounds that lead badly without stopping to clean the bore".

[DougGuy]

I load on a Dillon 650 and I'm pretty sure the powder would be spilling over the top with a double charge. I'll say it would be next to impossible.

Two points of discussion.. First and most important, do you have any more of those same loads assembled? If so, can you perform a push test against the side of your load bench or a vise or some solid object and see if you can manually push the boolit any deeper in the case?

(edit: if you *do* find any that move even the slightest bit, PULL these boolits so they aren't fired!)

The 40 runs at quite a high pressure to start with, and if you can set the boolit back even .010" by pushing it agaist something, then this is likely what caused the over-pressure event that blew out the case when it was fired. If there is not enough neck tension in the brass, and this can be like one or two or three cases out of a couple hundred that will push back and the rest of them will resist setback on the bench, I'd say you found the most likely culprit.

It could have happened as the slide stripped the boolit out of the magazine and pushed it into the feed ramp, could have also happened if for some reason one boolit may have been slightly oversized enough to jam in the barrel throat once there was enough lead built up, and the slide shoved the boolit deeper into the case when the gun went fully into battery.

With the 9mm and 40 at max performance, even the slightest amount of setback can be disastrous. As little as .010" in a 9mm can spike pressures to 60k easily.

Second point of discussion, the barrel doesn't have much throat in it, and you want to size to .402" I would be glad to take a look at the barrel and take a pin gage to it and measure the freebore, measurements may find some interference with the boolit shoulder, barrels I have throated don't lead anywhere near as badly as the photo shows and they feed anything and shoot lights out afterwards.

[FergusonTO35]

Hey Dougguy, you do any work on rifle throats?

[DougGuy]

Hey Dougguy, you do any work on rifle throats?

Not at this time and let's please not steer the Glock thread. I can do TC or removable barrels PM any questions please.

[garym1a2]

I had one case blow on me in my G22 with factory barrel and I only shoot a few hundred rounds thru it. I also have over 12k rounds in the same gun with a Storm lake barrel and never a problem. I only use the Lee 175gr tc bullet for all by 40SW.

[Patricklaw]

Two points of discussion.. First and most important, do you have any more of those same loads assembled? If so, can you perform a push test against the side of your load bench or a vise or some solid object and see if you can manually push the boolit any deeper in the case?

(edit: if you *do* find any that move even the slightest bit, PULL these boolits so they aren't fired!)

That lot of loaded 40 contains about another 175 rounds. They were originally seated with an RCBS die, carbide set if it matters on the seater, and crimped with Lee FCD. I have checked them and there is NO movement in the bullet. Setback is highly unlikely.

Second point of discussion, the barrel doesn't have much throat in it, and you want to size to .402" I would be glad to take a look at the barrel and take a pin gage to it and measure the freebore, measurements may find some interference with the boolit shoulder, barrels I have throated don't lead anywhere near as badly as the photo shows and they feed anything and shoot lights out afterwards.

To my knowledge, the barrel is a factory Glock. I have two other barrels for it, a lone wolf 9mm conversion and a Glock 357 sig barrel. It's fast becoming my goto handgun. (Nothing special, ugly, black. It just works.)

I really appreciate the offer to look it over but this was such a small lot of ammo that I'll never load again. I'll shoot the rest up in my Para 1911 and that lot of boolits, that I didn't make, will be gone forever.

[jdfoxinc]

What about plane base gas checks? Will they help?

[FergusonTO35]

They might help, if you are shooting stout loads and/or your lead is on the soft side. If your boolits are undersized and/or the lube is just not up to the task they will not do you any good. Size is generally key to successfully shooting boolits out of autoloaders.

[zubrato]

Wanted to add this little bit of info about how I load for my glock, as it has changed rather significantly over the years.
I now size the mihec 125HP/135 solid to .359, 50/50 pure and coww alloy with tin added for fillout, water dropped into ice bucket.
I get fantastic accuracy at 25-35 yards, groups size of half a fist, and at 10 yards I consistently and quickly shoot dimes, if not one hole groups.

Have shot the MP 147grHP I designed/honchoed and 155gr solid with similar results or better group sizes.

Used to chase hardness, but now I find I get better lubrication that the grease grooves can compress, and the lands/grooves are better filled.

The real key to 9mm loading is the expander. I will be writing RCBS and sending appropriate dimensions similar to the 38sw lee expander, so that I don't wear out my shoulder using it progressively on the pro2000 as I have been.

Best of luck to casters and reloaders.

[Oregon Willie]

Hi, I have a Glock #20 that I load with some molded Lee 150 grain lead that I load with 7.2 grains of Unique at 1,300 FPS and 562 FPE,
I have two barrels, the stock Glock and a Storm Lake which was purchased because of all the hype on leading the original barrels. I feel after putting thousands of lead bullets through both, I have concluded that if you do not clean your barrel on a regular basis, yes, you will have problems up to bursting your barrel but if you clean your barrel on a regular basis, and I clean mine after every shoot, you would be okay.
I purchased a Lewis Lead Remover from Brownells, but neither barrel has leaded enough to have used it as normal cleaning with a brass brush and some elbow grease has solved the issue.
I will finish by saying that common sense, checking the condition of the barrel, and cleaning (hard) on a regular basis will do. Glock knows that a dirty, leaded barrel will cause problems but not one that is cleaned on a regular basis, but they can't rely on customers doing that so they, as policy, state emphatically, don't shoot lead in our barrels!

[yondering]

Wanted to add this little bit of info about how I load for my glock, as it has changed rather significantly over the years.
I now size the mihec 125HP/135 solid to .359, 50/50 pure and coww alloy with tin added for fillout, water dropped into ice bucket.
I get fantastic accuracy at 25-35 yards, groups size of half a fist, and at 10 yards I consistently and quickly shoot dimes, if not one hole groups.

If you can shoot a Glock that well, you should find a local GSSF league, you'll clean house every match. I've been using my cast bullets in our local GSSF matches and find it good fun.

[FergusonTO35]

Today I had some time for shooting and decided to shoot up the last of my Lee 356-120-TC sized to .356. They were loaded over my usual load of 3.8 grains HP-38. I shot them out of my Glock 19 with both OEM and Storm Lake barrels. The Glock barrel shot them pretty well for the first ten rounds, then the groups opened way up. Switched to the Storm Lake tube and groups immediately went back to normal, actually better than the Glock barrel did at first. Upon cleaning I found quite a bit of lead in the Glock barrel, no big surprise there. If there was any lead in the Storm Lake barrel I couldn't see it, just powder fouling. Both barrels cleaned up easily, not surprising as both have shiny bores.

All of my 9mm boolits will be sized to .357 from now on. I've always had better luck with boolits on the fat side in every gun I've tried, not just Glock. I'm currently building a Glockenstein 22 with an LWD barrel from a gent here. Will probably size to .402 for that one.

[Catshooter]

I have a Glock with a .402 barrel. It's the only one; the rest are .400 or .401. But you never know 'till you measure do ya?


Cat

[ettore]

what was the weight and diameter of your boolits? Im having a hell of a time with my G19 and key holes