Stock Glock 9mm barrel in .40 Glock

[graycrait]

I watched a guy I know who has quite a few Glocks and many dozens of handguns clean plate racks and hammer other steel with his Glock 35 using a stock Glock G34 barrel and a 9mm Glock mag. When I talked to him about using a Non-conversion barrel he told me that he found that there wasn't enough slop in the stock 9mm barrel to .40 slide slide fit to worry about. Gun groups decently too.

How common is this practice? I had been under the impression for some years that a 9mm conversion barrel was required for converting a .40 Glock to 9mm.

[Patton]

I have about 350rds through a Glock 19 barrel in my 27. Shot groups are consistent.

[Warbird]

Dangerous practice. Its not just about slop at the end of the barrel, it is also about other spacings within the gun. It may group just fine, but it doesn't provide proper support in a gun designed to feed so reliably because it already is on the edge of chamber support as are most striker fired guns made today.

Just cause somethnig can be done, ie somebody has gotten away with it, doesn't mean it should be done.

Edited June 13, 2011 by Warbird

[bigwakes]

For the price of a $99 barrel it just ain't worth it. Get a conversion barrel.

[tercel89]

We need a side by side demension measurements and pics of the Wolf Conversion barrel and the G19 barrel .

This is an interesting thread

I have always wondered about it too .

[walton6467]

Do we have a Glock Armourer who can chime in on this? Enquiring minds want to know.

[Karnage]

For the price of a $99 barrel it just ain't worth it. Get a conversion barrel.

I made these measurements using a stock Glock 17 (9mm barrel) and a Lone Wolf 40 to 9 conversion barrel for a Glock 22 (.40 s&w)

chamber thickness measured from inside chamber to sidewall

Stock .108" Lone Wolf .115"

chamber thickness measured from inside chamber to top exterior of chamber

Stock .194" Lone Wolf .201"

Thickness at muzzle

Stock .107" Lone Wolf .117

[Troutburger]

Ok, so Karnage has proven there is some difference in dimensions. My question is how much difference does .007" make?

[walton6467]

So are we saying factory Glock barrels are dangerously thin? I'm not sure I understand that using stock 9mm barrel is dangerous in a different model, if it isn't dangerous in the correct model.

[Warbird]

And... What is the difference between the edge of the chamber and the bottom of the feed ramp. Between the overall width at the rear of the chamber, and the overall height from the top of the barrel at the rear to the bottom of the lugs? What is the difference in the circumferences of the barrels. Small difference can make for huge divergences when you are talking about machinery. The tolerances here are not extreme, but they are significant. If you measure the radius at the end of the barrel you get the illusion the difference is smaller than it is. Yet the circumference will prove otherwise. Ever noticed the difference in a hat with a 2" and 2 1/2". At any given point you would say 1/2" is nothing, yet when looked at in its entirety the difference is obvious.

We are also talking about several difference here, you can't simply point to one and say there's just a difference of this, does that matter.

[Warbird]

So are we saying factory Glock barrels are dangerously thin? I'm not sure I understand that using stock 9mm barrel is dangerous in a different model, if it isn't dangerous in the correct model.

Huh? I'm not sure what you are asking here. Nobody is talking about a standard Glock 9 barrel shot in a Glock 9mm gun as being too thin. They are talking about using a standard Glock 9mm barrel in the Glock .40 caliber handgun, instead of using a 40-9 conversion barrel in order to shoot 9mm in the 40 weapon.

[JimmyMac483]

I have also heard of people using a factory .357 sig barrel in a .40 s&w Glock. Is this also potentially dangerous?

[Seaslug]

Do we have a Glock Armourer who can chime in on this? Enquiring minds want to know.

It's a fairly common practice, and it is NOT dangerous. The only differences between a 9mm Glock and the equivalent-frame-size .40 S&W Glock are the bore diameter and the ejector. Everything else locks up the same. The only real benefit to conversion barrels is to take up the play between the muzzle and slide after switching to the smaller caliber (and to be able to safely shoot lead bullets in bulk).

[Seaslug]

I have also heard of people using a factory .357 sig barrel in a .40 s&w Glock. Is this also potentially dangerous?

No. The magazines are even identical.

[JimmyMac483]

Very good to know, thanks Seaslug!

[Warbird]

Very good to know, thanks Seaslug!

Correct the mags for the 357 Sig and the 40 are the same. The 357 Sig is basically a 40 cal at its cartridge base. The pressure difference is higher in the 357 Sig. Some people even use the 40 mags with their 40-9 conversion. They will usually work, but wouldn't use it for SD.

If people want to use a 9mm G barrel in the 40 go for it. For the money, I will buy the conversion. Small changes make a difference in engineering and there are differences here. Enough said. Again just because some people have had no problems doesn't mean it is a smart thing to do. This isn't simply about marketing here.

[walton6467]

Thanks. My questions have been answered.

[TnShooter83]

No. The magazines are even identical.

Almost....But the follower is different.

Not by much, but for some reason Glock decided to run a different one.

Back some years ago (like 5) I called GLOCK the company and asked

if I gould use a .31 barrel in my G22. The answer was:

"Yes if your G22 has 3 pins.

If is has 2, they advise not to.

And if you experiance any problem to change followers, but typically you do NOT have to."

As for 9mm barrel in a 40, It has been done.

There was a post on this about a year ago on another forum.

One guy 100's or even 1000's through his OEM 9mm barrel in his Glock 40 cal.

He never had problems.

But, as I recall it was/did cause wear to something.

I've searched for the post but had no luck finding it.

I believe the wear was to the barrel lugs, or slide.

The whole post revolved around proving you CAN run OEM Glock 9mm barrel in a Glock 40 slide.

Just be able to live with the fact that it does cause abnormal wear. So far I have NOT seen or heard how much wear

it takes to render the pistol defective and nonfunctional.

Edited June 14, 2011 by TnShooter83

[Seaslug]

Almost....But the follower is different.

Not by much, but for some reason Glock decided to run a different one.

Back some years ago (like 5) I called GLOCK the company and asked

if I gould use a .31 barrel in my G22. The answer was:

"Yes if your G22 has 3 pins.

If is has 2, they advise not to.

And if you experiance any problem to change followers, but typically you do NOT have to."

As for 9mm barrel in a 40, It has been done.

There was a post on this about a year ago on another forum.

One guy 100's or even 1000's through his OEM 9mm barrel in his Glock 40 cal.

He never had problems.

But, as I recall it was/did cause wear to something.

I've searched for the post but had no luck finding it.

I believe the wear was to the barrel lugs, or slide.

The whole post revolved around proving you CAN run OEM Glock 9mm barrel in a Glock 40 slide.

Just be able to live with the fact that it does cause abnormal wear. So far I have NOT seen or heard how much wear

it takes to render the pistol defective and nonfunctional.

You are correct about the followers being different, although the latest generation of followers have been designed to reliably feed hollowpoint ammunition in either caliber. I should have said the magazine TUBES (and springs) are identical. The end result is still the same: you can shoot either caliber out of the same magazine, no matter what is stamped on the rear.

As for the wear issue, it's more likely that your body will wear out long before you are able to wear the barrel out to the point of non-function.

[TnShooter83]

I have to agree with you there. I not seen a wore out Glock yet.

I'm sure some where out there is one, but if you can afford the ammo to "wear it out"

I doubt you'll worry about buying a new Glock.