The Glock vs. Cast Bullet thing

[FISH4BUGS]

Can someone tell me in 25 words or less about the polygon rifling thing and why you are not supposed to shoot cast in them?
Thanks,
Donald in NH

[felix]

Have no idea why or why not. Prolly not the rifling style, but the chambering style, and even that is a maybe because with handloads you can make adjustments for about anything reasonably not kosher. ... felix

[thegreatdane]

in 25 words:


It can be done (with meticulous attention to detail and precise execution of fundamental cast boolit theory). Mine shoot to mirrored finish with excellent accuracy.
now to actually answer the question:


lawyers got involved.

[jameslovesjammie]

Glock also says not to shoot any type of reloads. Poly rifling has been used on H&K's, Kahr's, CZ's and Smith's with cast: no issues .

(25 words)

[subsonic]

Lead buildup can raise pressures to the point that things break. (11)
Some can get away with it, if they know how. (10)
Good luck it's hard. (4)

[subsonic]

Read the sticky (3)

[NickSS]

I have a glock and a Baby Eagle that both have polly rifling and both shoot cast bullets just fine. I have put hundreds if not thousands of rounds through them and have never had an issue. Mine work better with fat bullets sized to 357.

[Dframe]

thegreatdane has the real answer above. Lawyers. But in truth the manufacturers have always tried to discourage use of handloads.

[Moondawg]

Testing has shown that it is very risky in glocks chambered in 40 S&W, and glock barrels. Some risk with 45acp Glocks. Much less risk with 9mm. It has to do with unsupported chambers and tolerances in glock barrels, as well as pressure the round is loaded to. Most people that shoot a lot of lead in Glock 40 S&W just go ahead and buy a drop in, conventially rifled barrel, which has a little tighter chamber and more chamber support. Brownells carries Storm Lake barrels, which work well, for about $160. I have seen a couple of 40 S&W glocks go Kaboom, with lead bullets at IPSC matchs. They had Glock Barrels. Never heard of a Kaboom with an after market barrel and lead.

[9.3X62AL]

What D-Frame said.

I had great luck running castings through a Glock 21 (45 ACP). I haven't yet tried that bit with the Glock 23 (40 Short & Weak), and having a Storm Lake aftermarket barrel removes the need to do so. That doesn't mean that I won't try it, but the SL barrel shoots better with castings than the OEM barrel does with j-words.......so the incentive is a bit lacking.

One of the more germane issues that gets short shrift within the "Cast Boolits In Glock Pistols" question is the natures of the calibers involved. 45 ACP has a long-established and well-documented positive relationship to the reloading hobby and to cast boolits. Even in the shallow-rifled 1911A1 barrels, castings of relatively soft alloys (e.g., wheelweight metal) get a good purchase on the lands and behave nicely, assisted in no small way by the gentler 1-16" twist rate and by the gentler pressures that run in the 20K PSI ballpark (generally).

The 9mm and 40 S&W are not what I would characterize as "beginner calibers" for reloaders, and that goes double for folks using cast boolits. They run at high pressures--most of their platforms use insanely fast rifling twist rates--and a boolit/bullet that seats too deeply on feedramp contact can produce catastrophic pressures that destroy pistols.

Where I see problematic potential is with newer/younger shooters who completely bypassed The Revolver Period that older folks all went through, which included the very forgiving calibers like 38 Special--without doubt the BEST introductory caliber for a new reloader that ever saw light of day. The 45 ACP is similarly forgiving, I should add.

The 9mm and 40 S&W are NOT FORGIVING. AT ALL. If the 38 Special and 45 ACP are dune buggies, then the 9mm and 40 S&W are helicopters--with the same number of mistakes issued to their respective operators at the outset.

Does this mean "Don't reload 9 and 40, esp. with castings?" Not at all. I would be a hypocrite to say that, since I load both with A BUNCH of cast boolits. What gives me the fantods is a new reloader sitting in front of a Dillon progressive without a depth of experience in crafting ammo, and expecting to rip out a zillion rounds to feed his/her Glock or H&K. YOU GOTTA GO SLOW AND CAREFUL WITH THESE HOTROD ROUNDS, because that is in fact what the 9mm and 40 S&W are--esoteric and advanced reloading projects.

OK, I exceeded the 25 word limit imposed by the OP. See the sig line for justification. :)

[Walt]

Read the "sticky" above. I load 9m/m, 40s&w, 10m/m, and 45auto for my Glocks. Success is not always easy but it can be done safely with good accuracy.

[Old Caster]

Because with a lead bullet it is easy to have one get shoved deep into the case causing high pressure. --19 words--.

When this happens no one has a clue why because they didn't feel or see it. If a gun fires when the action is a bit open, the case will rupture and while it won't be fun it won't be devastating because the gun doesn't explode but only the case.
40's run at very high pressure which makes it even worse and more likely.

[MtGun44]

+1 What Al said on 9mm and .40 S&W reloading in general. Advanced topic, challenges
beginners.

You will also not that there are no +P loads for .40 S&W. Think on that one a bit.

Bill

[ColColt]

Some years ago(maybe 15 or so) before I knew about the problems some have with the Glock 40 S&W, I had a G22, 2nd Gen model and was shooting lead SWC's in it with no problem. I had forgotten about that until the other night plundering through some of my old reloading goodies I had stored under the stairwell and found a couple boxes of nickle cases and a lead SWC in those rounds. I either overlooked any warning about lead and Glocks back then or just ignored it-don't remember which. I found lots of brass so I know I was shooting lead back then but they were store bought boolits. Never any Kaboom.

[NHlever]

I have seen one H&K damaged quite a bit by shooting lead boolits. It was a .40 S&W, and they were handloads using commercial cast boolits. Probably some lead build up from undersize boolits. The owner isn't crazy about trying it again in either his new H&K, or his Glock.

[twotoescharlie]

just had to try it. had an old glock 17, one of the first ones assembled here in GA. shot 4 full clipsl , 2 of the lee tumble lubed and 2 147 grain flat nosed. 68 rounds total, no trace of leading. was just curious as I have had this pistol for 20 odd years but have shot it very little.


TTC

[Edward429451]

I owned a G21 for 20 some odd years before giving it to my son and I shot cast through it the whole time I had it without problems. But I come from a strange land where they still taught common sense though...:bigsmyl2:

[Walt]

I have seen one H&K damaged quite a bit by shooting lead boolits. It was a .40 S&W, and they were handloads using commercial cast boolits. Probably some lead build up from undersize boolits. The owner isn't crazy about trying it again in either his new H&K, or his Glock.

I've not loaded lead for a 40s&w HK (I do for my 40s&w Glocks) but my two 45auto HK's shoot select lead loads very well.