One of the more interesting guns I came across at the police crime lab was a full auto .30 caliber Ruger. The original barrel was replaced with a section of the barrel from a M-1 carbine. When fired, the gas piston drove the cylinder pin into the hammer. In testing, it would fire two or three rounds, but the lack of buffering battered the components to the point of jamming. Just as well, considering the single-actions tendency to roll back in the hand. Where would it be pointing by the time round six fired?

Bob