Here is how it was explained to me in regards to the stoeger cougar, which is owned by beretta, and actually used to be manufactured by beretta:
Originally Posted by rccola712 View Post
silly question, but what exactly is the rotating barrel lockup? what exactly does this cause the gun to do when fired? thanks!
When the gun is fired (or cycled by hand), the rearward motion of the slide causes the barrel to rotate in position. This supposedly causes less felt recoil and is supposed to be more accurate. I think the less felt recoil is probably more noticeable with the 40S&W model than it is with my 9mm model. It's a very cool design. I'll have to try to get a picture of the barrel (maybe tomorrow) and you will see exactly what I'm talking about. The slide and barrel are in constant contact and alignment.
heres the thread if you want to read more, there were pictures, but theyre not on the there anymore for some reason: http://handgunforum.net/showthread.p...ight=rccola712
hope this helps!