[banddr2]

They couldn't, since it is a blow back design it would blow up

. There is not delayed lock up to allow the gases in the barrel enough time to leave through the muzzle. So anything with higher pressure than a .380 would release gas through the ejection port and into the magazine, and that would be bad.

 

[banddr2]

Michael, do you know if that Robar is a blow back design??

Kahr makes pistols in that caliber, I would like to try one someday because I think they would be a little punishing on the hand.

 

[banddr2]

Colt Mustang is a great little gun, I have never owned one though. I looked up in one of my books, Walther did make a PP in 9mm that was a straight blowback, it had a huge slide and still had trouble with part breakage, though they didn't say what parts broke. It looked like it used about a 5" barrel.

 

[banddr2]

Wow, that looks like one big chunck of stainless steel!!