New G&P M4A1 Carbine....Making Advertised Speed.

I recently received my G&P M4....and I'm loving it. It is advertised to shoot at 350fps to 400fps. I shot it through the chronograph today and its getting consistently 355-365fps. Well that is in the advertised velocity range, but I just wanted to know if there is anything I can do...tweaks, to get closer to 400fps? or tactically is there really any advantage to that extra speed? What are most folks shooting in the field?

I also bought a Lipo which says you might want to upgrade spring to M120 or above. Well I have a brand new M120 spring...but should I replace it? I might risk going above 400fps which is above at least I know Georgetown rules.

Any opinions or advice?

Well. FPS...... if it's lower.... it might be because the gun is built better, with more durable parts. Upgrading the fps really doesn't make all that much of a difference from 365 to 400. You're still getting more or less 1 joule of kinetic energy.