Quote Originally Posted by MPfiveengineer
Greater controllability and rate of accurate fire. If you are looking to suppress it I would go with the TROS 5in barrel. The problem with anything longer is keeping a 147grain bullet subsonic, especially at altitude.

As far as ballistics go I like 8.875in, but I am an MP5 guy :mrgreen: . A friend and I did some testing on .75" Plexiglas with a G17 and a MP5, both using WWB 115gr at about 10 yards. The G17 did not penetrate with 3 rounds while the MP5 went through it every time
Ok, noob questions here;
If it's the same round, what is the difference? Is the longer barrel on the MP5 getting more velocity out of the round or stabilizing better or what?
What's the deal with "keeping a bullet subsonic"?
Thanks, 2C