.40's threw your 10mm

[Overkill338]

I know there is a guy at GT with 10k+ rounds threw his with zero problems but his name escapes me.

How many of you do it.

Also please tell me how the reward or lateral forces are any greater than 10mm.

[sqlbullet]

The concerns:

1.  Misfires.  Since a shorty forty can't properly headspace in the case mouth, it relies on the extractor to keep the case head against the breech face.  If the extractor fails in that job, you can have a misfire, and potentially a hard to clear malfunction.  For range play, not the end of the world, but a Lone Wolf barrel is pretty cheap, at the cost of just a couple boxes of ammo.

2.  Blown primers.  In a perfect storm the firing pin will knock the case off the extractor hook(s), push it deep in the chamber and set off the primer.  In this case, the primer will partially or fully exit the case as pressure begins to build, then be crushed when the case head rockets backwards to the breech face under pressure.  Some of the pressure and powder could escape via the spaces between the frame and slide and give you a fun hot gas and burning particle shower.

3.  While pressure is within spec, the case head getting a running start on the breech face means a harder "hit" and potential damage over time.

All that said, most modern 10mm guns have pretty robust extractors. OTOH, a barrel for your Glock is only about $100, or the cost of 4-5 boxes of ammo.  Awfully cheap insurance.

[dred]

I've done it.

My Silverback and Mechtech will both cycle them.  I was done with'm as soon as this was confirmed.  And I'd swap in a lighter recoil spring if I had to face a steady diet.

I fired them evaluating emergency/SHTF options.  40 is a lot more common so I'm comfortable enough that I will consider it as an ammo option in the unlikely event things get that bad.

If you are thinking on trying in your 1911, I advise that you confirm the extractor is functioning correctly before bang switching.  Too many 1911s in the wild are running "well enough" with poorly tuned extractors.  I just think it is prudent to find out before dropping in a round that will head space with the extractor.

I do this often - firing 45ACP in 460 Rowland chambers.  The relatively low pressure of 45ACP is less worrisome.

[The_Shadow]

Well yes it has and can be done in some 10mm guns...That being said what you might see if you do shot 40S&W through the longer 10mm chambered guns.

The chamber is around an 1/8" longer in 10mm, so this places the shorter 40S&W casing away from the end of chamber cut.  The bullet has to traverse that gap of the chamber, so you can get bullet gilding metal or in the case of cast bullets alloy deposited on the sharp edge at the end of the 10mm chamber.  If you get a deposit of metal shaved and rolled up it can prevent proper chambering of the longer 10mm cartridge if not cleaned.  BTW this can happen with the proper ammo in some cases.  I had it happen with 45ACP and it took a good pick to release the piece of bullet material that prevented the next round for complete battery>

You will also get a buildup of carbon/soot from the end of the short 40S&W casing and up to the end of the longer 10mm chamber.  If you get a deposit of carbon/soot it can prevent proper chambering of the longer 10mm cartridge if not cleaned.

There is the risk of the shorter 40S&W missing the extractor and sliding deeper into the chamber where a misfire can occur because the firing pin or striker may fail to reach the primer.

There is also the risk of improper feeding for any number of reasons due to the cartridge being slightly shorter, such as nose diving on the feed ramp.

Recoil systems seem to have little effect as many guns cycle properly even with extra powder springs for the 10mm high impulse ammo.

[Overkill338]

You should always use a good copper and lead solvent. I prefer the foam.

[Ridgerunner665]

I've done it, while I won't recommend others do it....I didn't have any trouble with it through the Glock barrel.

I won't do it with the KKM barrel though, not that it would hurt it, but that's not what I got it for.

[Overkill338]

I'm more interested in 9x25 Dillon than .40 S&W.