[AoiShikaku]

With what is said above. Any tightbore barrel will work for your 1911. In regard to the FPS, for one you are lucky to get it at 350 perfect and two the FPS Increase will be anywhere from 0-7 FPS difference (depening on the inner diameter of the barrel, you could get more). If you really want the accuracy a longer tightbore barrel will help you more so than anything else. So a suppressor with an extended inner barrel would work. Might want to go with a 6.03 to a 6.05 inner barrel (I found a 6.01 gave me shit groupings compared to the stock barrel). Also adding a few stripes of black electrical tape around the internal barrel to make the barrel wobble less while in the external barrel helps to have more consecutive shots.

In regards to the 650mm barrel you can do what I suggested with the 1911. Get a long enough suppressor and a few barrel spacers and you're back in business on you l96.