I do understand the braces are the same. You can even use the same trigger group from one to the other. I kept the spare trigger group for years before a friend wanted it more than I did. Both guns were cleaned and recoil and hammer springs were changed on a regular ~8-10K schedule. My point was the gas venting system is different for the 390 vs. the 391. There is a difference in the action cycle/timing/harmonics between the two guns, which I believe the 391 "buffers" the cycle better. I also realize the 390 requires less cleaning that the 391. I am specifically talking about the gas venting system on the 391. Lastly in the previously mentioned 391 with 80-90K of shells thru the gun, I never had the twisted carrier syndrome. This came later and was attributed to a change in manufacturing. My daughters and wife all experienced his hitch with later 391 production guns. The original cure was to replace the 391 carrier with a 390 carrier then later a re-bending of the carrier was deemed the cure. I believe you could send in the bent 391 carrier to Beretta and they would send you back a carrier that had the proper bend or twist. The carriers were twisting which caused improper shell alignment when feeding into the chamber. I like the Beretta 390/391 product line, but feel that the 391 was a better gun for my application. You will see the 391's that currently flood the market dry up in the future as there will be no more made. All indications are the 400 will be the semi-auto Beretta workhorse of the future and there are good early reports on the 400.
