.40 S & W shotshells in a 10mm

[bernie]

I recently saw a post on Glocktalk dealing with on shooting .40 S&W shotshells in a 10mm Glock 20. Several people posted and kind of indicated that they had done it. Am I wrong in thinking that this is not very likely? Doesn't it headspace on the case mouth like other auto pistols? If that happens, how would it work? Thanks for your input on a question of simple curiousity.

 

[PO2Hammer]

I have a Glock 20 and have shot a couple mags of .40 through the 10mm barrel. It actually fuctioned perfectly. The extractor holds the rim for the striker. It is hard on the extractor, so I stopped after about 20 rounds. I wanted to make sure it would work in a pinch. I bought a conversion barrel so I could do it safetly and have put about 2K rounds of .40 through my 20.