Question on glock: Flash marks on the side of the casing

[Daisy'sDad]

I agree with all the posters that a "less" supported
chamber aids in feeding. Not an issue.

However, which poster in these threads has used an after
market barrel on their Glock that has, according to the manufacturer,
a fully supported barrel?

The OP's question was about flash marks, and I can tell you
without question that my Lone Wolf barrel (which is "fully supported") does not leave the
flash marks that my OEM barrel does.

Sorry Mr. Steele, but I have seen more spent Glock brass than
most, and if they are using a stock barrel, there will be flash marks.
But what do I know...I'm just an internet armorer.

[Bill Steele]

I agree with all the posters that a "less" supported
chamber aids in feeding. Not an issue.

However, which poster in these threads has used an after
market barrel on their Glock that has, according to the manufacturer,
a fully supported barrel?

The OP's question was about flash marks, and I can tell you
without question that my Lone Wolf barrel (which is "fully supported") does not leave the
flash marks that my OEM barrel does.

Sorry Mr. Steele, but I have seen more spent Glock brass than
most, and if they are using a stock barrel, there will be flash marks.
But what do I know...I'm just an internet armorer.

I don't think there is any doubt guys run aftermarket barrels to gain added case head support, but that is usually when they want to push the envelope on the high side of pressures in straight walled calibers (nuke 10mm loads come to mind).

On the other hand, a know a lot of guys that run aftermarket barrels in their competition guns for greater perceived accuracy (usually not LW though).

Anyway, at the end of the day, I think the OP got his question answered.

[alexisjohnson]

This is with standard factory ammo. 230 grain federal fmj...

And there is sometimes a bit of gas that blows back...

[ojisan]

When a round is fired, the case expands and grips the chamber walls.
The expansion seals the gas flow from going back around the case and into the breech area.

A low power / low pressure round may not have enough pressure to expand the case enough to seal.

If the chamber is too large in diameter for the case expansion to seal the gas flow, you will get blow back into the breech, even with a high pressure round.

Many competition rounds are loaded hot to make major, so usually this ammo will expand and seal well.

Loose chambers feed well and are more tolerant of ammo dimension variances. (Military type guns usually have large chambers).

Tight chambers position the bullet more precisely in the barrel throat and usually are more accurate.

[Carcassonne]

Hey guys,
Had a question/concern. Is it normal to see flash/burn marks on one side of the casing when it ejects? I have a glock 21 and i tend to see a lot of cases with powder/burn marks all the way from the lip all the way to the end of the case. This is of course with brass (can't notice anything with the steels).

Normal or is this a bad sign?

It is normal with some powders and reloads.



.

[alexisjohnson]

So then...i should assume that the chamber is too loose if i'm seeing this stuff with a full power round?

[ojisan]

The case contracts quickly as soon as the pressure drops.
Powder may still be burning in the barrel, causing some blow back.
As long as burnt powder and hot gas is not spitting back in your face, it's OK.

A sign that your chamber is too large is lengthwise case cracking and splitting.
This happens once in a while when everything is OK (bad brass), but if the gun does it a lot with all kinds of ammo a new barrel should be considered.

[Eljay]

So then...i should assume that the chamber is too loose if i'm seeing this stuff with a full power round?

What constitutes a "full power round"? A lot of factory ammo is pretty weak these days and as noted .45 isn't exactly high pressure to begin with.

[Oceanbob]

Perfectly normal.

This^^^^^

Glocks are built for WAR. They purposely make the chamber about .007 thousandths larger than normal so they will Run with battlefield ammo.

No worries.

Be well
Bob.

[Carcassonne]

So then...i should assume that the chamber is too loose if i'm seeing this stuff with a full power round?

A lot of my 45ACP reloads have powder burns. Even the +P loads. I doubt it is the chamber. If the gun shoots good, don't worry about it...or you could call Glock and ask them. They should no more about their guns than anyone else on Calguns.


P.S. My 44Mag always has powder burns, but I know it isn't the gun's fault; it is the powder I use.

[alexisjohnson]

Sent it in for the heck of it. Best be sure vs always wondering

[1911whore]

It is normal. If you reload do a FULL resize and tumble them good.....do not sweat it

[alexisjohnson]

So glock just got back to me. Check this out:

We have received a Glock Model 21 slide and barrel, serial number XXXXX into our warranty department. 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

I got this handgun (first one ever) last year and i put about 1k through it. I noticed the issues from the very beginning. What in the world could have caused this? I've never used reloads...just standard factory ammo. Any ideas?

[Carcassonne]

I got this handgun (first one ever) last year and i put about 1k through it. I noticed the issues from the very beginning. What in the world could have caused this? I've never used reloads...just standard factory ammo. Any ideas?

See answer below.

So glock just got back to me. Check this out:

We have received a Glock Model 21 slide and barrel, serial number XXXXX into our warranty department. 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

I got this handgun (first one ever) last year and i put about 1k through it. I noticed the issues from the very beginning. What in the world could have caused this? I've never used reloads...just standard factory ammo. Any ideas?

Personally I find it hard to believe that the barrel could be damaged. It must have been more than one round that did the gas cutting. What brand of ammunition did you use?



.

[alexisjohnson]

I've used federal, winchester white box, and some cci. No reloads...and nothing crazy has happened. No rapid fire...just basic practice.

1k total through it (cleaned every 200 rounds)