Can you shoot.40 S&W through a 10mm Glock 20? (VIDEO)

Solid proof-of-concept video by MattV2099 who we know for his many, many Glock abuses torture tests.

This actually doesn’t surprise me all that much as the external dimensions of .40 S&W and 10mm Auto — case length notwithstanding — are identical. The .40 S&W will chamber normally and headspace off the extractor. Given that most commercial 10mm loads are within the realm of possibility for .40 S&W in terms of muzzle energy, 10mm pistols would have to cycle it pretty reliably as well.

The one thing you’d have to worry about is fouling if you switch from .40 to 10mm without cleaning the barrel first and maybe throat erosion in the long term. Fouling is probably the real thing to worry about, because if there’s enough build-up in the chamber, the gun could foreseeably partially-chamber a 10mm cartridge and fire it out of battery. Clean it after .40 S&W practice and it’s not likely an issue.

‘Course you can avoid all of that with a .40 S&W conversion barrel.