Skip to main content

I did the same with a G23 using  KKM conversion barrel. I called KKM and asked them if I needed to swap any other parts. I was told no, just the barrel and mags.

The G23/19 with KKM barrel has been boringly dead nuts reliable at just over 2500 rounds now.

It is quickly becoming my favorite carry gun. It’s a fricken’ laser beam.

That being said - I also converted a G35 to 9mm with a Lone Wolf Alpha Conversion barrel. On this one I swapped out all the internals on the slide to 9mm correct parts (I used an Apex plunger and failure resistant extractor) and installed a 9mm trigger housing for the proper “bent” ejector. This one has also has thousands of rounds through it - also with zero malfunctions.

I would just drop in the barrel and use 9mm mags and see if there issues. If there are, convert to 9mm slide parts and 9mm trigger housing.

Caveat - I wouldn’t carry it until I had at least 1000 trouble free rounds of duty ammo through the converted pistol.

I also had a G23/19 and G35/34 conversion.  It took about 100 rds for the G35/34 conversion to become reliable, and then no issues.  I did not change out anything in the slides.  I first used a 9mm ejector block in the G35, but later switched back to the .40 ejector.  From then on, all I did to change calibers was to change the barrel and magazine.  No problems.

The 9mm ejector is "bent", the .40cal is straight.  The .40S&W rim diameter is 10.8mm.  9mm rim diameter is 9.96mm.  So we are talking about a 0.84mm difference in diameter, or 0.44mm in radius.  It is my understanding that the .40 ejector was made straight to avoid the potential that when ejecting a live round, the 9mm ejector could impact the primer, causing an out of battery discharge.  

-Caveat - I wouldn’t carry it until I had at least 1000 trouble free rounds of duty ammo through the converted pistol.-

Big roger to this.

I have a gun I built with an 80% frame, a LWD G23 slide and an S3F G23 9MM  barrel with generally Glock internals, and another I cobbed together with a Glock frame and slide, and a Storm Lake conversion barrel. I don't have quite that round count yet as I have to come back to CONUS to shoot them- but so far, so good.

I am sticking with replacing all caliber specific parts to 9MM- extractor, ejector for example. 

Why would someone do this? To see if it works, and because some of us are the kinds of guys who see a bunch of parts and think, "If only I had a XXXX and YYYY, I could have another pistol!"

Note-- Just tried putting the .40 S&W barrel back in to one of the slides. IF you replace the extractor & ejector with 9MM versions, you may have some real problems. 

Another note-- sticking with as many OEM parts as you can is usually a good thing. The more after-market parts stacked on top of one another, the more chance of something not working. I had an Apex 9mm extractor in one set up. Apex does not recommend using their extractor on anything but Glock OEM slides with Glock OEM barrels. One set up I have works fine- the other needed to have a real live Glock extractor. 

Last edited by Community Member

I'm with you guys....I have a Gen 4 G23 that I bought from my agency when we went to 9mm.  I was going to shoot up the rest of the .40 ammo I had on hand.  Had it milled for a RMR and bought a Storm Lake conversion barrel and a 9mm ejector housing.  I still haven't installed the 9mm ejector as the pistol has been boringly reliable without it.  Round count probably 2000 or so.  I don't carry it on duty simply because I have a G19 that I carry daily, but at this point I'll be comfortable doing so if I decide to.    

I have a 22 and a 23 that I did this to.  The 22 is with a KKM barrel, and the 23 is with a Lone Wolf.  The 23 is milled for an RMR.  Both, as has been stated already, are boringly reliable.  I think both of them got rebuilt with 9mm parts in the slides, but the 22 still has .40 cal ejector.   Neither are carry guns, but both have been test beds for frame projects (The 22 got cut down and is essentially now a 19L and the 23 is on a Timberwolf Frame.) 

Its a great way to keep a 40 in the stable as a just in case...

Let me add to the utility of a .40 gun.  My G35 had a 9mm barrel, and a .22 conversion.  And of course, if it needed to be a little bit shorter, a G17/22 slide group.  While easily feasible, I've never been tempted to get a .357 Sig barrel.  To my mind, the conversion factor has nothing to do with .40 cal being better than 9mm.  However, we once lived through an ammo shortage where getting your favorite caliber wasn't an option.  If you can shoot 2 or 3 calibers out of the same gun, it might keep you shooting where a single caliber left you high and dry.

Dorsai posted:

 If you can shoot 2 or 3 calibers out of the same gun, it might keep you shooting where a single caliber left you high and dry.

I came back to CONUS for a few years in December 2012. After one of the mass shootings, the only available handgun ammo was .40 S&W. I had originally purchased the G23 because we had a shit ton of .40 in our ammo storage and no gun to shoot it. When I got back to the US, having a gun in .40 allowed me to have a CCW gun.

I never tried the .357 Sig round-- so I have no idea of its capabilities and limitations. I do hear that .40 guns beat themselves to death, so swapping out the .40 barrel for a 9MM barrel was a nice feature.

I did the same w/a super cheap Gen 3 23 that I picked up w/dead night sights (so old they were staked!) that was nasty and was just filthy all around. A lot of TLC, sight replacement,  switched out  the factory 40 bbl to KKM 9MM conversion one and brand new mags. After about 900 rounds of various types, weights and manufacturers  of 9MM I stopped counting and its my 3rd line back up. I might swap everything that was .40 OEM to 9mm OEM this "Black Friday" depending if I find a good deal on OEM parts. As aside but related, I know that other guys Im buddies with that have done this cal conversion with the non Glock "lowers" have had a lot of issues, FWIW 

I had a glock 23 gen 2 that I converted with a lonewolf 9mm barrel. I carried it for awhile like that and sold it off and went with new Glock 19s for the wife and I. I didn't have any problems with the LW barrel and would probably have kept it but that glock 23 gen 2 was old and you could tell it was old......

Solid info above....

I am glad I ditched the .40 cal for .9mm... 9mm is much cheaper to shoot, easier to shoot and the glock 19 mags match up great with my ruger pc 9 

stray round posted:

Any preference or pros/cons on these conversion barrels?

I actually had 2 Lonewolf barrels and never had trouble with any of them. The only thing I didn't like was there was a picture of the Lonewolf business logo engraved above the chamber last barrel had some weird proof stamp on it too...looked like some kind of tracking mark or maker mark....of course it had nothing with function etc...

That's my .2 cents

Got my Alpha Wolf conversion barrel a few days ago.  After changing the magazine out, I went to the range and burnt up 200 rounds with and without the WML on.  The pistol did not blink. 
I went to the range the second day and tried another 100 rounds of a different grain and still had no issues.  Ejection was positive and accuracy was where I was intending the rounds to go. 
Kinda liking this so far and should’ve done it sooner. 

86Bear posted:

For those of you that had the Gen 3 Glock 23 that had the reliability issues when attaching a WML, did the 9MM conversion eliminate this problem?  I would love to do this with an RTF2 G23, but only if I can put a light on it. 

That has been my experience. WML Gen3 Glocks should only be in 9mm.... .40 SW works best in Gen4 Glocks with WML. Gen5... I have not messed with yet.

I have a Lone Wolf 9mm conversion barrels for both my Glock 22 and Glock 35.  (and a Storm Lake conversion barrel for my Smith & Wesson M&P in .40 cal, and a Bar-Sto conversion barrel for my Sig 226-DAK in .40) 

I did it because 9mm ammo is cheaper than .40 cal ammo. I have no plans to use the 9mm barrel for defensive use.

I did read that Lone Wolf had a bad batch of barrels that were slightly out of spec, but I haven't had any problems with mine. I haven't shot them a great deal, either. But so far I'm quite impressed with the accuracy.

 I use 9mm magazines with the 9mm barrel.

 I did not have to change the ejector or extractor.

 BarSto and Storm Lake and KKM precision also make conversion barrels.

 I think a 9mm conversion barrel is well worth considering if you have a Glock in .40 cal. It would allow for cheaper practice, an another option should ammunition availability become an issue.

 (I also have an Advantage Arms .22 conversion unit for the Glocks and a Sig .22 conversion unit for the Sig)

Add Reply

Copyright Lightfighter Tactical Forum 2002-2020
Link copied to your clipboard.