However, the G20 can very easily be converted to shoot .40SW and .357Sig which derive from the 10mm Auto case. Only a barrel swap is needed. Unlike many other conversions, these are actually pretty reliable-- no extractor fishiness and radical changes to proper recoil spring pressure, etc. This adds a lot of versatility and aids the ammo availability aspect.
Glock G20 .40 Conversions | eHow.com
Well, according this, they can't be converted. If the frame size is the same as a G21, then the magazines wont fit in the magazine well. If this article is wrong, please someone de-bunk it! Thanks...
That article is incorrect. Using the 10mm mags will work with .40 and .357 sig because the casings are the same diameter. There will be front to back space as 10mm is longer than the other two. I know at least Lone Wolf sells barrels to do such a conversion, and I've heard its reliable. I dont have experience with this conversion, but I know its been done many times before.
Can you? I thought the G20 ran on the same frame size as a G21... am I wrong?