Glock Conversions

[JohnKSa]

This sounds like grounds for a whole new thread.

Believe me, it has been the grounds for many threads.

If the topic interests you and you'd like conclusive information based on measurements and scientific analysis rather than anecdotal "data" and speculation, look into purchasing a book called "The Glock in Competition" by Robin Taylor, et. al.

One chapter covers the subject of lead bullets and polygonal rifling in detail. That chapter was written by a licensed professional forensic engineer who fired literally thousands of bullets through Glocks with instrumentation monitoring the testing.

 

[TruthTellers]

^ If the lead bullets were powder coated, would it be okay to shoot them in the Glock barrels?

 

[Sapper771]

I have fired many thousands of lead 9mm bullets through Glock factory barrels. I do not recommend it.

Lessons I learned along the way:

-9mm with lead bullets is a long hard road.

-Using copper remover on your bore before you shoot lead helps quite a bit. Or, just having a dedicated lead bullet barrel. Lead sticking to copper easily, which is where a lot of my troubles were coming from.

-Chore Boy copper scub pads are the best thing for scraping the leading out of your bore.

-I was casting a Lyman 122gr TC bullet. It has a huge lube groove. I mixed two bullet lubes to make a softer lube.

-I sized these bullets to 0.358" due to the bore slugging in at around 0.357".

-Load development was firing 20 rounds and checking for leading. Record results. Clean barrel. Shoot next lot. Repeat. Since I was looking for a cheap IDPA training load , accuracy was not the top concern, leading was. Accuracy could be tweaked later.

-People were telling me that I needed to get my bullets up to a BHN of 22. I tried that at first, but it was not working for me. I learned what obturation was and began using a BHN of 12 to 14.

-Read all the Glen Fryxell (Los Angeles Silhouette Club) articles you can. He is the reason I became successful. Thank You Glen!


As far as conversion barrels, I tried a few. Their chambers are tighter than Glock factory chambers, thus all the brass that has been previously fired through a factory Glock barrel will not fit due to head expansion (AKA Glocked brass). I called a few barrel manufacturers and asked if their barrels matched the tolerances of a factory barrel. I then got lectured about how dangerous it was to reload for Glock pistols and how the factory barrels weaken the brass, which is why I needed to buy their barrels. Thats why I gave up on getting a groove and land barrel for my Glocks.

Coated bullets didnt really work for me. They still leaded the barrel and left the powder coating residue in the bore as well. I guess because they were .356" and not .358". Bullet diameter is crucial.

 

[TruthTellers]

Okay, so Glock barrels are probably best not to shoot lead through them. Got it.

Does the brass get weakened a lot after being shot in a Glock barrel? How much does shooting a case in a Glock barrel shorten the cases life by?

 

[AK103K]

I shoot 9mm in a number of Glocks and I shoot it to failure, and it lasts a good long time. Id say it lasts as long as brass shot in anything else.

 

[Sapper771]

Okay, so Glock barrels are probably best not to shoot lead through them. Got it.

Does the brass get weakened a lot after being shot in a Glock barrel? How much does shooting a case in a Glock barrel shorten the cases life by?

I have 9mm brass that has 20+ loadings on them, all through Glock 26/19/17/34 factory barrels. My loads arent hot, (115gr @ 1125 FPS). I have noticed that most of the time the primer pockets will loosen up before the necks will split. When I notice the loose pocket, I mark the case with a sharpie so I can scrap it after the next firing.

I would love to have a land and groove barrel with the same chamber tolerances as the factory barrel.

 

[AK103K]

I have 9mm brass that has 20+ loadings on them, all through Glock 26/19/17/34 factory barrels. My loads arent hot, (115gr @ 1125 FPS). I have noticed that most of the time the primer pockets will loosen up before the necks will split.

Thats interesting. My loads arent a lot different than yours, 124grain fmj's at around 1125fps. I think I figured I was getting somewhere in the range of 30 reloads with a lot of brass before I really noticed a lot of failures/issues.

I know my brass is going when I start seeing split necks and start getting an increasing number of feed issue malfunctions, stove pipes, brass to the face, etc.

I only just recently saw a loose primer pocket, which was my first (and only that I know of), and it was with a new lot of once fired brass.

After swapping the extractor out and back a couple of times with my one 17 I shoot all the time, I finally figured out that my BTF issues were brass related, and not an extractor problem. The rims get chewed up by the extractor from the constant cycling, and will eventually start to cause random function issues. It actually works out OK, as you now get to more realistically practice your malfunction drills, since they occur unpredictably.

 

[LiveLife]

I would love to have a land and groove barrel with the same chamber tolerances as the factory barrel.

Many post about Glock barrels' generous chambers but my 9mm KKM/Lone Wolf barrels have comparable chamber dimensions and case base support as factory Glock barrels.

And my 40S&W Gen3 Glock barrels have comparable case base support as many other factory barrels (like M&P).

 

[Sapper771]

Many post about Glock barrels' generous chambers but my 9mm KKM/Lone Wolf barrels have comparable chamber dimensions and case base support as factory Glock barrels.

And my 40S&W Gen3 Glock barrels have comparable case base support as many other factory barrels (like M&P).

The problem is that almost all of my 9mm brass is from police ranges. Even after full length sizing, the brass will not drop into both of the Wolf barrels I had due to the head expansion. I contacted Lone Wolf about it and they confirmed it.
After that I had to buy new brass and factory ammo in order to create some "non glocked brass" just so I could use it in the Wolf barrel. In the end, it was more hassle than it was worth.

 

[AK103K]

After that I had to buy new brass and factory ammo in order to create some "non glocked brass" just so I could use it in the Wolf barrel.

How long ago was this?

About seven or so years ago, I had a LWD 40-9 9mm conversion barrel for my 31, and most all the 9mm shot out of it, were reloads using brass that came from my 17's and 26's.

The only issues Ive heard of in this respect were with the .40's.

 

[PO2Hammer]

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.

I stand corrected, that is a very good reason.

 

[Sapper771]

How long ago was this?

About seven or so years ago, I had a LWD 40-9 9mm conversion barrel for my 31, and most all the 9mm shot out of it, were reloads using brass that came from my 17's and 26's.

The only issues Ive heard of in this respect were with the .40's.

It was around 2009-2010. I got the barrels shortly after getting into casting.

 

[AK103K]

I know the .40's shot in Glocks had the bulging issue, but I thought they addressed that. At the very least, they have dies to deal with it.

Never saw a 9mm Glock that caused the brass to swell and cause a problem though.

 

[greyghost01]

I just spent days researching this same issue, From what I understand to go from 40 to 9mm is no problem, Unless your talking the 35 and then because of extra weight change the barrel and spring and use a glock 17 mag and you will have great results some say their 35 is a tack driver with the 9 conversion. The 40 or 10mm in the glock from what Ive read you are better off changing everything to go to 9mm the 40 is really heavy duty, And the use of +P is a must, The 10mm to 40 just requires spring and barrel. I gave up on 10mm due to the lack of 10mm and the crazy cost of what is out there 40.00 a box is to much when I can buy 40 for 16.00 and 9mm for under 12.00 I checked on 10mm brass and couldn't find any in my area.

 

[PO2Hammer]

All you need for 10mm to .40 in a Glock is a conversion barrel. The 20 and the 29 run just fine with .40 with just a barrel swap. Even reduced power .40 handloads cycled my guns just fine.

 

[Deanimator]

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.

Other than for EIC matches, I handload ONLY lead bullets for handguns.

I hate plated bullets having had a lousy experience with the garbage that National Bullet used to put out here.

I bought Storm Lake cut rifling barrels for my Glock 19 and Glock 22. They work just fine and were drop ins.