Glock Conversions

No experience starting with a 10mm, as I started with a g23 in .40sw. I got a lone wolf barrel for 9mm, and some mags and it runs flawless. No extractor swap, no spring swap, no nothing.

Just a guess, but I bet you would need a different recoil spring at the very least to shoot 9mm from a 10mm sprung gun. Possibly an extractor as well...10mm is alot longer than 9.

I use KKM/Lone Wolf 40-9 conversion barrels in my Gen3 Glock 22/23/27 and have plans to use 10-40 conversion barrel for Gen3 G20SF.

- Older generation 40S&W Glock magazines did not always reliably feed 9mm (especially last 1-2 rounds) but newer generation magazines have worked well so try your 40S&W magazines first before buying 9mm magazine.

- Worn mag followers and/or worn mag springs will also cause feeding issues but can be corrected by replacing with new mag followers and/or springs. With replacement mag springs, I prefer to use Wolff +10% extra power springs - https://www.gunsprings.com/GLOCK ®/cID1/mID5/dID116#148

- All of my KKM/Lone Wolf 40-9 conversion barrels have been true "drop in" and did not require any fitting for proper function in my Glocks. I run stock extractor and do not have issues with spent case extraction/ejection.

- Glock 17 and 22 models use the same recoil spring assembly and various factory 9mm ammunition and reloads have worked reliably to cycle the slide and extract/eject spent cases when using conversion barrels - http://www.midwayusa.com/product/35...il-spring-assembly-glock-17-22-24-31-34-35-37

- Lone Wolf conversion barrels (and most other conversion barrels) use 1:16 twist rate and my KKM conversion barrels use slower 1:20 twist rate. Depending on the load, KKM barrels have produced slightly smaller shot groups over Lone Wolf at 25 yards but both brand barrels have produced comparable to factory Glock barrel accuracy with jacketed/plated bullets and greater accuracy with lead bullets - http://www.thehighroad.org/showthread.php?p=9939834#post9939834

- While you can shoot 40S&W in 10mm Glocks (headspacing off extractor/loaded to 10mm length if reloading), I am planning to use 10-40 conversion barrel for the 20SF. 40S&W feed reliably from 10mm magazines and stock 10mm recoil spring offers softer recoil.

As to 10mm to 9mm conversion, thanks for mentioning it (Did not know about it) as Lone Wolf Distribution does sell a 6" conversion barrel (requires 11 pound recoil spring and use of +P ammunition) that I can use in my Glock 22 also - http://www.lonewolfdist.com/Detail.aspx?PROD=623362&CAT=241

A little digging found this thread regarding 10mm to 9mm conversion - http://www.glocktalk.com/threads/lone-wolf-g20-conversion-to-9mm.1513185/

I have not done the exact conversion that you are wanting to do, but here is what I have done. I have a Glock 22 in .40 S&W, I have converted to 357 Sig and 9mm. So far it has been flawless with all calibers.

I got a lone wolf barrel for 9mm, and some mags and it runs flawless. No extractor swap, no spring swap, no nothing.

Click to expand...

Pretty much my experience as well.

I had a LWD 40-9 for my 31 (357SIG), and I never had any issues. I did normally use my 17 mags in the gun though.

My 9mm mags work fine in my G27 with a 9mm LWD barrel.

Why not buy a 9mm to shoot 9mm?
Will you really flip flop between calibers?

Jim Watson said:

Will you really flip flop between calibers?

Click to expand...

I do most of my range practice with conversion barrels in my Glocks.

After the range session, I pop out the conversion barrels and pop in the factory 40S&W barrels along with a few drops of Breakfree.

Why not buy a 9mm to shoot 9mm?
Will you really flip flop between calibers?

Click to expand...

I would say if youre planning on shooting 9mm, its best to buy 9mm.

In my case, with my 31, I did it because of the beating the gun was taking from 357SIG, and ended up shooting only 9mm out of it.

I had a number of SIG's in 357SIG, with spare .40 barrels, thinking it would be a good thing to have the option. It was a waste of money. I shot the .40 barrels a couple of times to confirm they worked, and then they sat on top of a couple of cases of .40 doing nothing, until I sold them.

Bear in mind that your POI will be different when you change calibers

Click to expand...

I didnt find that to be the case, at least with the 9mm out of the 357SIG gun. I believe Glocks use the same sights for many of the calibers/models too.

I've got a 9x19 barrel for the Glock 20. It barely cycles. Some nuclear loads might help. Mags seem to work. Wouldn't count on it for anything serious though.

40 to 9 is no big deal lots of people do it.

Ah, OK.
I don't own or want a .40 or 10mm, so the temptation to buy big and shoot small isn't there.

I have three Lone Wolf barrels for my G20: a 357, a 40 and a 10mm (for cast bullets). The 40 has been deeply throated so I can load 40s to the same length as 10mm. All three rounds feed from the standard 10mm mags just fine.

Cast bullets in polygonal barrels is a whole other discussion, some say yes, some say no, I just use coated bullets. I still have some plain lead bullets around, but I plan on buying only jacketed, plated and coated from now on.

I've had KKM .40 conversions for both a 20 and 29, both ran 100% using stock 10mm springs and mags. Factory .40 ammo would even cycle my 20 with a 20 pound spring on a tungsten guide rod.

The 29 barrels both hit the same POI, but the 20's .40 barrel hit 2" to the right of the 10mm barrel at 25 yards, no big deal.

Both KKM .40 barrels were clearly more accurate with plated bullets than the stock 10mm barrels, but no better with good jacketed bullets like HAPs or XTPs.

During the 2008 component shortage is was nice having the .40 barrel because I could use small primers, large primers were nowhere to be found.

I don't know if 9mm in the 20 is worth chasing. IIRC, you have to modify the feed lips of a 10mm mag, run super hot loads, and use weak springs, sounds like a recipe for frustration.

Quote:
The 40 has been deeply throated so I can load 40s to the same length as 10mm.

Click to expand...

"That is sort of the key to reliability in guns chambered for longer cartridges."

You can load .40 long in the 20/29, no problem, but there's no need to. They feed just fine at standard OAL. I tried to make my jam by pushing some rounds forward and some back in the mag, never a bobble.

The only failure I had was making a light load with a long OAL. I loaded some 165 plated FPs with 5.0 HP38 in .40 brass to an OAL of 1.200", they shot 806 fps and were too weak to cycle, so I took the remaining rounds home and re-seated them to 1.135". Then they cycled 100% and ran 895 fps. So all you need to do is hit the minimum power required and a Glock will cycle .40 ammo at any OAL.

.40 in a 10mm Glock is a sweet deal. Recoil drops right off, function is 100%, accuracy is every bit as good and the non-handloader can save good money.

I've got a Glock 29, and I think it is the greatest thing ever.

I bought some Lone Wolf barrels for .357 Sig and .40 S&W. My Glock 29 handles everything I throw at it.

EVERYONE should own a Glock 29. Greatest Glock ever made, IMHO.

You can load .40 long in the 20/29, no problem, but there's no need to. They feed just fine at standard OAL. I tried to make my jam by pushing some rounds forward and some back in the mag, never a bobble.

Click to expand...

Oh yeah, there's a need to...the need to get near 10mm performance from cheap 40 brass, saving my Starline 10mm brass for only the good stuff.

The 40S&W case is a strong one, and since it used a small rather than large primer pocket it is actually stronger across the head than 10mm. If you seat out to 10mm OAL you get very nearly 10mm powder capacity and can (with what I consider to be an acceptable level of risk) load nearly to 10mm levels. I use the maximum 40 load for a given powder and bullet as near starting for my "40 long" rounds.

There's no way one would fit a normal 40 magazine, but I am very careful to keep 40 Long segregated from the normal 40 ammo. One thing I do is to only load one specific 200 grain cast bullet. If it's a 40 with a 200 WFN then it's close to 10mm in performance.

I can't shoot cast bullets in a polygonal barrel?

Click to expand...

There's a novel to be written on the subject, but the condensed version is "maybe." It is an order of magnitude more difficult than with conventional rifling, and there are numerous credible reports of dangerous levels of bore-obstructing leading accumulating after only a few rounds. Bullet selection, sizing and alloy are critical for success. Most commercial cast bullets are completely unsuitable for Glock barrels in my experience: too small, too hard and too poorly lubed.