40 Cal: Non-supporting chambers

[soldernut]

Hi all, looking for a little advice here...

I'm in the market for a 40 S&W cal pistol and have recently posted some other questions here. Now this crops up..

I've heard that some manufacturers rushed their 40 cal pistols into production by "opening up" their existing 9mm designs with the result that the feed ramp intrudes into the chamber, leaving the cartridge unsupported in the 6 o'clock area.

Well, I think the 40 has been around long enough that there should no longer be any excuse for this; which doesn't mean it isn't still being done. Perhaps it presents no functional problem, but I handload, and I don't need to deal with a bunch of fired brass with bulged cases.

I wonder if some of you with experience could tell me which pistols are known to have these non-supporting chambers, and which most definitely do not.

Naturally, before I buy, I will insist that the dealer field strip the gun, insert a new, unloaded 40 cal case (which I'll hand him), and let me inspect the chamber.

But you can save me some wasted time by narrowing down my search.

Thanks in advance.

 

[revhigh]

Glocks were always known to be the worst offenders of the unsupported case in .40, but they've reduce the unsupported amount over the years, and generally don't have many problems anymore. Years ago, if a 40 was shot out of a Glock, it was just understood that the brass was now junk. There's TONS of info about the Glocks on the net regarding this.

It's nowhere near the problem that it used to be.

CZ's, Sigs, XD's, M&P's, HK's, have never really had any unsupported chamber problems that I know of ... that's not to say that there aren't any. A recent or new Glock will be just fine, but if you want to shoot lead, especially with a high pressure round like the 40, you may want to grab an aftermarket barrel by Barsto, Lone Wolf or KKM. They have grooves in the barrels, and not the polygonal rifiling that the Glocks have. Personally I shoot lead in my G26 all day long, and have never had an issue, but the 40 is higher pressure and has less 'leeway' in an overpressure situation.

If you stick with a CZ75B platform, or the Sig 226 platform, you'll be fine from a barrel perspective, and most likely from an accuracy persepective.

Inaccurate guns are really annoying.

REV

 

[gb6491]

Personally I shoot lead in my G26 all day long, and have never had an issue, but the 40 is higher pressure and has less 'leeway' in an overpressure situation.
REV

I was under the impression that 9mm Luger and .40 S&W both run at about 35,000 CUP (with 9mm +P running at about 38500).
Regards,
Greg

 

[revhigh]

I'll take your word for it GB, I thought the .40 was considerably higher than the 9. Been shooting lead out of my polygonal barrelled G26 for 3 years or so ... thousands of rounds .... never had an issue, and I'm not a fanatic about cleaning guns, either, if you know what I mean. I generally clean a gun right before I sell it, unless it gets really bad and won't run. Well, not totally true ... but almost. :D

REV

 

[pistolpete]

Late to the topic, but I had a glock 40 and a round would "rattle" in the chamber more than my smith and ruger pistols. I understood that glock intentionally made the entire chamber slightly larger to aid in reliable feeding. I never had any bulged cases with my gen 3 glock. I suppose any polygonal rifles barrel like what comes on a glock or HK will not be as good as a conventional rifled barrel when it comes to shooting lead bullets. I guess i personally wouldn't worry about it. As many glocks are out there, and as many rounds go through them I wouldn't worry about an occasional kaboom every year. It's like winning the lottery.....extremely rare. :D

Also the barrel wall is thinner on some of those 40 cal pistols that were created from an existing 9mm design. For example, my glock 22 barrel was thinner than the barrel on my m&p 9.