Glock 20 case bulge

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Tennessee_Ted

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I got a G20 a few months ago. The pistol shoots like a dream, without a single failure in the 1,000 or so rounds through it so far, but it sure is expensive to feed.

I reload for all my other guns and I am set up with dies for the 10mm, but after resizing a few cases, I just can't see how reloading cases that are so badly bulged can be safe. I've even noticed (and thrown away) some cases that had smiles on relatively low-pressure loadings.

I know a lot of folks say they reload 10mm from factory Glock barrels with no issues, so I'm wondering if my chamber is a little looser than some. This brings me to my question.

I've been looking at buying a KKM barrel. I shoot jacketed or plated bullets almost exclusively, so I would be making the purchase solely to have a tighter chamber to save brass for reloading.

Can I expect an aftermarket barrel to make that much of a difference?
 
are you sizing the cases all the way? the directions that come with the die set should show the correct way to size the case.

i have heard nothing about 10mm case bulge (especially low pressure loads).

luck,

murf
 
I am sizing them as far as my die will let me. I am not using a bulge buster. My concern is more that the brass appears to have expanded so much. I know I can drop a few bucks on a bulge buster to make the cases look right, but I am afraid I would be asking for a case failure.
 
What generation is it. I know this was common in gen 1 Glocks but has been fixed. Wolf barrels also fixed this but I don't know about others. Glocks have bigger chambers then some other manufactures but that isn't what caused the bulge. The feed ramp being cut deeper then the case head left unsupported case wall & that is where the bulge came from. This is also what lead to do many Glocks blowing up. It's also why I'm just now getting a Glock. I always disposed of Glocked brass.
 
It's a Gen 4. That's why I'm wondering if my chamber is a little generous. The smiles I've had were obviously due to the feed ramp. But the case as a whole seems to expand an awful lot.
 
It may help. I've ran plenty of full house loads through mine, with a drop in KKM, and have had no issues with it.
 
what load are you loading ?
Too Hot ?
how many times has this brass been loaded ?
 
I bought a Gen 1 in early '90's from a Gulf War '91 vet who needed cash.
I had a S&W 1006 too, at the time.
I had been loading for the Smith with top end loads using Acc#7.

I started firing a magazine of rounds. On the third shot, I felt a "sting" upon firing. The Magazine had been blown out of the reciever, and the bolt stop blown from the frame. No permanent damage was done due to flexing of the polymer frame. Inspection of the fired cases revealed that all three had failed at the case head, only the third allowing sufficient gas volumn to vent to the reciever.
The next release of data from Accurate Powdwrs was reduced by ~15% across the board. Not a lot hotter than .40S&W.
Due to changing interests/needs, I sold off both guns. I have a couple of.40's. They are sufficient for my needs.

Funny, I've killed more deer with the .40 than all other handgun cartridges combined... And with 155gr going the speed of those 200gr XTP's from the 10.

I suspect you have a "loose" barrel. You may get several loadings from the brass before they actually fail. An aftermarket barrel might be cheaper in the long run. .40 brass is common. 10mm not so.
 
Cerosafe is an easy way to check chamber dimensions, alot of people also slug the barrel even for new guns, I've always heard they had generous chambers but unsure of the 4th gen, if in doubt I've heard good reviews on the lone wolff barrels.
 
One man's case bulge if another man's normal case. Just different perceptions of the same thing.

We have seen ordinary 9 and 45 pistols produce an expanded case if the chamber is on the loose end of SAAMI chamber dimensions. Before buying a new barrel I always check dimensions on the one I have.
 
Lose chambers won't cause the smiley. That is ether from a unsupported chamber or to much case pressure. Tight Group can cause this.
 
All the rounds through the gun have been factory ammo, except for fifty rounds of a warm load of Longshot in new Starline brass.

The smiles have all been on Armscor ammo, which I would attribute to lower-quality brass on a Glock feed ramp. The other factory ammo through the gun has been either Remington or Sig.

From the recoil (which I know doesn't equate to pressure), the Remington seemed like a fairly typical 10mm factory load. The Sig's claimed velocity suggests a full-power 10mm load. The felt recoil would seem to support that.

All the cases fired through the gun seem to have expanded more than any other round I reload for, judging by the significant bulge at the bottom of the case after resizing.
 
Whatever the cause be sure not to work a reload too low if you do not let it expand to the chamber you run the risk of running gas against the chamber walls, whatever the chamber dimensions are the brass will expand nominally to it so overall expansion can just be glocks way of reliability seen it plenty from them, Also as a side note I've been reloading ten for a couple years and my Lee dies don't seem to size the full length leaving a ring at the bottom that ultimately causes a need for the bulge buster even though I reload it mildly (tanfoglio witness fears) I get maybe 5 reloads before I air to (over)caution. I have enjoyed the reloadability of the SIG ammo btw I believe it's just starline but don't quote me
 
I'd talk to Glock about the factory stuff. As you said recoil tells you nothing. I wouldn't tell them that you are a reloader tho.
 
I shot my G 20 4th Gen yesterday.
Starline brass, 180 gr FMJ FN with 9.0 gr Longshot

Not a earth shattering load, but stout enough for thick cardboard,:)

Brass had been loaded several times.

No bulge or smiles.
 
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