What in the world is gas cutting in a glock barrel?

[alexisjohnson]

So i bought a gen 3 21sf glock about a year ago, put about 1k rounds through it and i noticed that the cases that were coming out had flash marks on one side. Sent it in for the warranty look and they got back to me saying the barrel had gas cutting. This is what they said:

We have conducted an initial inspection and found the barrel has gas cutting which is caused by faulty ammunition/case separation. This type of damage is not covered under warranty and the following options apply to the repair or replacement of this pistol:

A replacement barrel can be purchased for $125.00 Plus CA sales tax of $10.00.

So....here's the thing....i don't use reloads...only standard ammo. What in the world could have caused this? Glock is obviously saying its not their problem....but on my end i haven't really done anything to warrant any damage like this... it had this issue from the very beggining.

Any ideas as to what could have caused this? In addition, is it worth buying the barrel from them or should i go aftermarket?

[bazineta]

Gas cutting is the term typically used when a cast bullet doesn't fully obturate into the bore. Not sure what context they're using it in here. If you'd ever had a case separation, you'd remember it, frankly.

If you've got to replace the barrel anyway, I'd probably go with a Lone Wolf or something similar, so that you've actually got the option to shoot reloads.

[alexisjohnson]

Yeah...i've never had anything even close to case separation.

What are the benefits of getting a lone wolf barrel over a standard glock one? Will accuracy or reliability improve?

[JustEd]

Alex, please post some pics of the discolored cases.
This does happen sometimes on my 38+p loads when
Using CFE Pistol powder, but not on 45 reloads.
Yes, I understand you are using factory ammo,
just want to see how bad the problem is.

[alexisjohnson]

This isn't my pic but my cases looked the same...

http://www.xdtalk.com/threads/what-causes-this-case-discoloration.161911/

first pic

[leadstorm]

When a shot if fired in a gun (rifle or pistol), the design intent is that it forms a closed system until the bullet leaves the bore.

At the front end, the bullet should (mostly) seal off the gases by obturating (squishing outward) in the barrel.

At the back end, the brass is basically just a gasket. It's supposed to seal off the combusting gases from traveling rearward. There could be a lot of reasons that it does not, including: the powder burn rate, the brass hardness, the timing of the gun, chamber looseness, etc.

With .45ACP, there can be a huge variation in SAAMI-compliant factory ammo based on the components they use. Glock tends to be generous in their chamber dimensions to ensure reliable feeding, but a looser chamber is harder to seal.

If the cases were just coming out like that picture, it's actually fairly common to see and I wouldn't have worried about it. It's interesting that Glock thinks the barrel is dorked at this point...

From MagSafe's FAQ:

7) For greater safety and less wear on customer's guns, we now use .38 Special +P nickel brass for the .38 MAX, & Triton's .45 Super brass for the .45 MAX and .45 Super SWAT Loads. Glock 45s have huge throats; be careful.

[bazineta]

It's common for cases to look like that, especially if the loads are on the lighter side. I've never regarded it as a big deal.

I'm not a Glock guy, so the next bit here isn't something you should take to heart without verifying first. On the subject of aftermarket barrels, commonly they'll have standard rifling instead of Glock's polygonal rifling, which they say you can't shoot lead in, for reasons unknown to me. Aftermarket barrels will typically have a fully supported chamber, which leaves the brass looking better and thus more likely to be reloadable easily. Aftermarket barrels will be often cut to a tighter spec than a factory barrel, especially if you go with a match barrel, which may contribute to better accuracy.

I'd suggest hitting Youtube for a few videos on the subject to get an appreciation for what's available. However, if the cases are just discolored a bit on one side, I'd just shoot it, frankly.

[teflondog]

Yeah...i've never had anything even close to case separation.

What are the benefits of getting a lone wolf barrel over a standard glock one? Will accuracy or reliability improve?

A stock Glock barrel has an unsupported chamber. That's one of the reasons why people replace their barrels, especially in .40 S&W. Another benefit is that you can shoot lead out of an aftermarket barrel.

[Bill Steele]

When a shot if fired in a gun (rifle or pistol), the design intent is that it forms a closed system until the bullet leaves the bore.

At the front end, the bullet should (mostly) seal off the gases by obturating (squishing outward) in the barrel.

At the back end, the brass is basically just a gasket. It's supposed to seal off the combusting gases from traveling rearward. There could be a lot of reasons that it does not, including: the powder burn rate, the brass hardness, the timing of the gun, chamber looseness, etc.

With .45ACP, there can be a huge variation in SAAMI-compliant factory ammo based on the components they use. Glock tends to be generous in their chamber dimensions to ensure reliable feeding, but a looser chamber is harder to seal.

If the cases were just coming out like that picture, it's actually fairly common to see and I wouldn't have worried about it. It's interesting that Glock thinks the barrel is dorked at this point...

From MagSafe's FAQ:

Spot on.

I would be shocked if your chamber/barrel was in any way different than it came from the factory.

Forget about it and enjoy the gun.

If you really want an aftermarket replacement barrel, my opinion is KKM is the best. Just know that if you get a Lonewolf or KKM barrel, you are likely to still get scorched cases when you are running ammo loaded a little light pressure wise. 45 Auto is a low pressure round to start with, so it is very common to get scorched cases.

[hermosabeach]

The most extreme gas cutting I have seen was on a blown/ pierced 50 BMG primer... The hole and jet of gas cut into the bolt face....

Glock barrels have always been loose to aid with reliability...

Lone wolf and KKM are a tighter chamber and a more supported chamber...

They also do not have polygonal rifling so lead bullet are safe....

[Germ1]

This isn't my pic but my cases looked the same...

http://www.xdtalk.com/threads/what-causes-this-case-discoloration.161911/

first pic

most of my cases look like this, don't know why you're worried about it. 15,000 rounds through my Glock and no problem. Glocks have loose tolerances, pretty sure this is a normal occurrence.

[Lead Waster]

I'd just buy an aftermarket barrel if I had to get a new barrel.

[robert101]

Remove the barrel from your Glock, take your small finger (put some oil on it) then insert into your chamber and see if any rough or bad spots exit there. I agree that some soot can be normal. Also, it is very unlikely that the factory barrel is now un-usable after 1,000 rounds. See if you can feel any disturbing contours in the chamber.

[lakersfan]

Had quite a few cases look like that on my last range trip. I think it was Blazer Brass 124 grain casings. A G17 was used. I will check my brass later tonight.

[alexisjohnson]

Well i had already sent the gun back to glock for a looksee. The armorer there had inspected it and he mentioned this issue with gas cutting today. Basically, he said that gas had leaked into the chamber area and essentially melted/burned the metal. He said it was caused by ammunition.

At first they wanted 135 to replace the barrel but another replacement barrel was found...so they'll be switching the barrels and sending it back to me.

Frankly...the whole thing is strange but hopefully the issue is resolved with this new barrel. The thing is i've only used decent ammo...so the whole thing is a mystery to me.

This is my first glock and first handgun

Also i did attempt to get the original barrel back so i could inspect it (based on what you guys have advised) but glock said they can't send it back and it will be destroyed (prob... liability issues)...