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Old 08-07-2012, 12:48   #3
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Join Date: Nov 2011
Location: PRK
Posts: 2,402
Originally Posted by pasky2112 View Post
Hi Everyone.
Forgive me for starting a new thread on this subject but I've been reading GT for many days...literally...researching this topic. I see a VERY wide range of responses to the below questions that I'd like to propose they be aggregated in this thread.

To the point, I have a new G20 (my first 10mm) coming and planned to just shoot it stock with some factory loads (PMC) and then reload those and handload some new Starline and Win brass. But I keep seeing pictures of blown cases, glock smiles and the like from folks loading hot/nukes in a stock Glock bbl. Since 10mm brass isn't laying all over the place like .40 S&W, I'd like to preserve the ones I buy best i can using the bbl I paid for with the gun. ;-)

That said:
If one likes to load hot, would it be better to get an aftermarket bbl with a 'better' chamber? I use a KKM in my .40's just to preserve brasslife...I'm not sure they are more/less accurate, IMO. Any preferences/experience re: AM bbls like SL, KKM, etc.?

I'd like to work up safe max loads in .40. Can I shoot reloaded .40's out of the G20 stock bbl RELIABLY /ACCURATELY... relatively? ;-)

Since quite a few shooters report they shoot .40's out of their stock and/or AM 10mm bbl's, what's the point of conversion bbls?? (10mm-.40, that is) Is it the 'use it for what it's designed for' principle?

Has anyone ever just dropped in a 6" AM bbl in place of the stock G20 4.6" bbl and felt it shot well? ...better? Why did you swap bbls?

Thanks to all in this forum and everyone sharing their experiences!
Let me start by saying I am a newbie to 10mm loading. Guys like Taterhead, Yondering, Shadow, Meathead9, Robert91922, et al have probably forgotten more about loading this round than I will likely ever learn.

My experience is that my KKM barrel's provide a small improvement in chamber support, but I personally don't think it is a required improvement if you are staying anywhere near sane loading (I am talking specifically about Glock 20/29 here, the difference in my KKM and stock G21 barrel is more pronounced).

My personal opinion is that smiles occur when you are over the pressure line and occur more because of timing issues than because the stock ramp is cut too far into the chamber or the chamber is too loose. I do think tighter chambers can cut down on how far a case stretches, so may help with brass life, but at $.15/case for new Starline, I think you would have to shoot a great deal of extremely hot loads to make up the price difference of what an aftermarket barrel will cost and save you in cycles.

I bought a KKM 10-40 conversion barrel for my G20SF. I have shot alot of 40 loads through it and it works perfectly in that application. My 10-40 barrel came as a non-dropin (I had to fit it) and also had a generous freebore already cut in it. I suspect this barrel was intended for a smith as I needed to fit it and likely was originally destined for a competition shooter who planned to shoot a long loaded lead (hence the freebore cut). I fit it to my slide (not as well as a smith probably could have done) and it works fine. With the generous freebore that my barrel came with, I have been able to load my 10mm loads with 40S&W brass (basically more powder and longer OAL like a 10mm round) and shoot them through my conversion barrel without a hitch. It was after that experience that I tried shooting 40 and 10mm loaded in 40 brass out of my stock G20 and G29 barrels, they feed and shoot perfectly. The one caveat I do have to say is both of my G20SF's and my G29SF are newer guns and the mags are also newer. I think no magazine I have has shot more than 3-4K through it, so the flawless feed of 40 brass through my 10mm barrels has to be kept in perspective, I don't know if the flawless feeding will continue when mags start to wear and actions start loosening up.

I guess all of the above is a lot of anecdotal blather to say, hold off on an aftermarket barrel for a while, stay inside the lines loading hotter 10's until you get familiar with the gun, the brass, the powders you are using, etc.

The 10mm is a wonderful round, whether loaded in 10mm brass or 40 brass, enjoy the ride and don't be in a rush.

Last edited by WeeWilly; 08-07-2012 at 13:15.. Reason: Left Robert off the guru list, how could I do that?
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