450Bushmaster.net

Brian,

If you upper is a carbine, the Daniel Defense Omega 7.0 Rail I have in the classifieds would set off your rifle! hahah

It will freefloat the barrell, NO Modification necessary!

I have used a couple of yankee hill machine forearms and only needed a punch hammer and the tool that came with my hand grinder(dewalt) fit the barrel nut perfect. It only took 5 min to change so you may check into them.