KKM G21 10mm conversion-Range report

[kjm1016]

Walter GA and I have both been working with this conversion, and comunicating results via e-mail. We are using standard length slides and barrels. Results have ranged from dismal to merely disappointing. Using standard springs and 180 grain jacketed loads, I averaged 2-3 jams for every 10 rounds. Bear in mind these are my reloads, close to maximum but within safety limits. The data source for these loads was the Speer #13 and the Hornady #6 manuals. Replacing the springs with a 22-lb. spring with steel guide rod improved performance somewhat. The loads now jam at a rate of 1-in-10. The jams are all of the same type. The case appears to have been released early by the extractor and end up jammed between the upper part of the breach face and the top of the barrel hood. What appears to be needed is a 10mm extractor that will fit a G21. (Note: a G20 extractor will NOT fit a G21.) Modifying a G21 extractor does not work. All you end up doing is ruining the part. Fortunately, they are easy to replace. If someone made a 10mm extractor for a G21, I'd buy one! Vendors take note.

The irony of this is that all drop in conversions are not created equal. I have a 9mm Storm Lake barrel for my G23 and it works just fine. Sorry I don't have better news, folks. If you are considering the G21/10mm conversion, I wouldn't bother. Save your pennies and buy yourself a dedicated 10mm pistol. In due course, that's what I'll eventually end up doing. Other than the Delta Elite or the G20, does anyone else make a good 10mm?

[freakshow10mm]

Glad to see WalterGA is still alive and kicking.

Dan Wesson's Bobtail is supposed to be good. 40 cal 1911s can be readily converted to 10mm. I am almost finished with my Para P16 10mm conversion. Barrel ream to 10mm, flat bottomed FP stop, and heavier recoil spring. All for under $100. Just waiting on the barrel to arrive. Then a 19 shot 10mm blaster.

Other than those, I don't know. Well, besides Glock. Witness is supposed to be good too. A number of them on here. Choices are limited. Shame.

[Clarkbar]

Originally posted by kjm1016
The case appears to have been released early by the extractor and end up jammed between the upper part of the breach face and the top of the barrel hood. What appears to be needed is a 10mm extractor that will fit a G21. (Note: a G20 extractor will NOT fit a G21.) Modifying a G21 extractor does not work. All you end up doing is ruining the part. Fortunately, they are easy to replace. If someone made a 10mm extractor for a G21, I'd buy one! Vendors take note.

Was the G21 extractor you were using the newer "LCI" type or the older style? That is the standard parts swap discovered by Colorado Glocker (as the originator of the G20L long-slide conversion) and indicated to all of us that went with the G21 long-slide and 10mm-chambered G21 profile 6" barrels.

[salvo]

I have talked to as many people as I could regarding the 45-10mm conversion here on GT. I have found that the conversion seems to be a hit or miss proposition, most people that I have talked to that have the long slide conversion seem to be real happy with it, using the LCI extractor w/ spring loaded bearing and after market recoil rod/spring.
Others that have tried different combinations seem to have mostly extraction problems. Most have had a few feeding problems at first but seemed to go away with brake in.

Like Clarkbar, I too am wondering if you are using the LCI extractor and what is your total conversion consist of?

I would love to hear both sides of this conversion, my G21 is all ready to go, I just updated the ejector, LCI extractor and spring loaded bearing. Tested the upgrades this past weekend and it ran flawless as usual with WWB .45 ACP.
Now I have to decide what path to take:freak:
45-10mm Long Slide or buy a G20?

[Roneye]

I switched to the LCI extractor and that made a big difference but I was still experiencing an occasional failure to extract then I found the spring loaded bearing pictured below the spring loaded bearing in the foreground is the stock Glock slb. The one in the background I got from lone wolf and it is about a 1/16 of an inch longer than the stock one which gives your extractor additional holding power. Since I installed the new spring loaded bearing I have not had a failure to extract. Show the picture to Dan at Lone Wolf and I am sure he can hook you up.

http://bianco.cc/spring loaded bearing.jpg

[salvo]

Roneye, my new spring loaded bearing looks like the bottom one in your picture and my old one looks like the top one?
When I installed it I thought the long one would be better. I'm even more confused now!

BTW I bought the LCI & SLB from GlockParts at the same time.

[Roneye]

Sorry about that I got that all bass ackwards, I am currently using the top one with my conversion barrel. I also throated my barrel and then polished the chamber and that seemed to help as well.

[ColoradoGlocker]

.

[salvo]

Roneye, thats OK about the mix up, thought I may have put the wrong one in. But thats a great idea you came up with to give the extractor more bite!

[Lumpster]

I recently installed a 45/10 KKM in my G21, and tried a new "dual spring " recoil spring from GlockDoc . With the standard spring, the slide speed was so fast the ejector would kinda broach cut the back of the case, causing the case to stay put on the extractor. The new spring and LCI extractor is working fine so far, but this gun is only going to be used for hunting. I'm working with Longshot powder and XTP bullets, starline brass.

[Quarterbore]

I have not been around a whole lot and I just replaced my Glock 21 so I looked these old threads and I am disapointed to see the results. I am tinking that if I want to shoot 10mm I need to buy a Glock 20 upper and 10mm ejector and use that on my Glock 21 frame and just forget about the conversion barrel.