10mm and lead

[horseman]

So I am reading conflicting information concerning lead or am not understanding what I am reading. I have shot thousands of rounds of 9, 40 and 45 using Missouri Bullet cast bullets. No problems. I have begun playing with a stock Glock 20 10mm and would like to use the 180 gr. Missouri Bullets I use in my forty. On the MB web page they use a formula to determine what a good Brinell hardness to use based on pressure (CUP) generated by the round. 10mm being around 31000 to 35000 pressure would seem to need a much harder bullet than the 18 Brinell ones I would like to use.

Then there is the Glock barrel vs lead bullet deal. The Buffalo Bore website says, if memory serves, that the leading problem occurred in Glock barrels using pure lead with a Brinell hardness of about 4 and that hardened cast bullets are not a problem.

I am using Longshot at 9 grains, oal of 1.26, and a Hornaday 180 gr. jacketed HP traveling at 1200 fps. I sure would like to use the MB lead bullet with that same load. Anyone have any actual experience shooting lead at 10mm velocities especially using a stock 20 barrel?

[noylj]

I find the whole pressure/BHN idea dumb. FIT is #1 and the lube is #2. I think it is a way to justify the way-too-hard alloy all the commercial casters use now.

My 10mm Autos are quite happy with 11-15 BHN bullets--bullets are either commercial but at least 0.0015" over groove diameter or they are as-cast and NOT sized (usually 0.402-0.403"). My cast bullets are softer than commercial, and the commercial are about 15BHN, and not the std. 20 BHN.

However, I don't have a Glock with "strange" rifling.

Try it. Just don't shoot 100 without inspecting the barrel. The worst that can happen is some leading in the barrel, and that is easily cleaned out.

[G29SF]

I have owned KKM barrels since I bought my G20SF and G29SF. In addition I have purchased-and-shot and loaded-and-shot lots-o-rounds of 10mm. Including HOT stuff. The only reason I am saying all of this is to let you know I am no stranger to 10mm.

I use longshot for most of my 10mm loads. My favorite hot-yet-safe (hot enough for fun, yet enough room for powder-drop-errors) load is 180gr Hornady FMJs with 9.5gr of longshot.

In all of my research, I have read that the only issue with lead in Glock "polygonal" barrels is lead build-up over time. Most guys (and when I say most guys, I am saying guys that are really "into" this stuff... not just new shooters) say there is not issue with lead as long as you check-clean your barrel.

Not all lead is created equal either. The harder the lead the less of an issue the build-up is.

I recently started to purchase "lead" bullets (I say "lead" because it is a mixture that is harder than regular -- much like hard-cast) due to having a hard time finding bullets. (I have the luxury of knowing a guy who makes his own bullets for resale -- not just for himself.) I shoot them without any issues... although it is in my KKM barrels and not Glock barrels.

I would shoot the lead and watch for build-up. If you don't see any issues... shoot away!

[Croomrider]

Try it, I used to shoot cast lead wheel weights out of a 44 mag at 1400 fps, and had no problems.

Mike

[jmbaccolyte]

I've had more trouble from too hard lead alloy bullets that were too small a diameter, but mostly I shoot milder practice loads. Also I don't own a Glock. But here's a link to the cast bullets forum:

http://castboolits.gunloads.com/index.php

There you can guys who shoot nothing but lead alloy bullets.

PS: Bronze wool (from the Home Depot type stores) wrapped about a worn out barrel brush will clean out lead deposits well, if you don't get it right the first few times.