Originally Posted by minitrukin

I believe you can change the barrel in a G23 to a G19 so you can shoot 9mm instead of .40. Is that correct? Is there anything else that would need to be swapped out along with the barrel? Also can you go from having a G19 and put in a G23 barrel to shoot .40cal? Thanks in advanced

That is incorrect, somewhat.

You'll need a conversion barrel, since there will be a lot of slack when putting in a G19 barrel into a G23 slide. (A Glock in .40S&W can be converted to a 9mm or a .357SIG with a conversion barrel).

In the same way, if you have a G19, you can only convert it to shoot .380, 9x21 and 30 Luger.

Go look into KKM, Lone Wolf, Barsto or Jarvis barrels for more details.

im not sure the .40cal extractor will pull the 9mm brass out correct me if im wrong though also u will need mags

The slot in the rear of the slide cutout at the breechface is the problem area for these types of conversions. If the new cartridge has a larger base/rim diameter than the original cartridge that the slide was designed for, it cannot be converted (no way to get a .40 barrel to work in a 9mm slide), as the round is simply too big for that notch in the slide/breechface. Going to a cartridge with a smaller base/rim diameter will usually work, as the larger extractor will usually catch enough of the smaller round's rim to extract and eject it (although most makers of conversion barrels only suggest they be used for training/practice, and NOT personal defense, due to the possibility of stoppages). Cartridges with the same or very similar base/rim sizes will have no problems (.40 to .357, or opposite). So, here is what you will need to do most common conversions:

9mm to .40 -- Cannot be done without a new slide and probably ejector.

.40/.357 SIG to 9mm -- Special conversion barrel (NOT just a factory barrel in the new caliber; that won't work) and magazines for the new caliber.

.40 to .357SIG OR .357SIG to .40 -- New barrel (usually can use a factory barrel, OR an aftermarket drop-in barrel). Old mags will probably work.


Note on the magazines: although mags in other calibers MAY work, or might be "tweaked" to work, I recommend against it, for two reasons:

- Loading ammo for one caliber into a magazine marked for another caliber is a potential problem waiting to happen. It would be very easy to accidentally load a 9mm round into a .40 barrel, and on firing, the case would probably split and release hot gasses into the action, possibly damaging the gun or injuring the shooter or bystanders. Same for chambering a .357 round in a .40 barrel.

- "Tweaking" magazines for another caliber may compromise their reliability in the original caliber. You don't want to screw-up the reliability of your primary weapon/caliber just to save a few cents during practice/training, do you?

I recommend spending the extra bucks to get a few magazines in the proper caliber for any conversions, and only have one caliber of ammo/mags/barrel out on the firing point at any one time. When you switch over to another caliber, completely clear off all the old stuff and put it away, and confirm that only items for the current caliber are on the bench. It could save you a lot of problems.

Hope this was helpful.

very well put sir

Just to add 10mm to .40 cal only need Special conversion barrel. 10mm mags will work for the .40

Well, i have a Glock Mod 23, I also have the storm lake 357 sig con barrel and it works great, I also have the lone wolf 9mm con barrel, and use glock 19 mags, I have never had a problem with ejection works great. I have a really good buddy that is a glock armor and checks my gun all the time and no were issues at all. So yes the 9mm conversion will work with the 23.