Well, if not for duty use, I'd recommend trying a lower rated spring and swapping out buffers. I like trying out Carbine, Heavy and H2 buffers. Just be sure to try out some of the lower power ammo to make sure your setup is reliable. I've seen alot of great reports on Vltor's A5 setup.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul