Glock Caliber Conversions

[tmaca]

I've heard that it's possible to convert a Glock 10mm to .40 S&W with a barrel change. Is that true and, if so, does it work the other way? Could I fire 10mm from my .40 Glock by changing the barrel?

[Chuck Haggard]

Yes, you can run .40S&W and .357Sig from a G20 with the appropriate barrels, but no, a 10mm round is too long to fit in a G22.