i ended up with a bunch of spare uppers and i want to build them out myself. what all tools do i need to accomplish this task. thanks.
At least a 4" bench vise
Something to clamp the upper in the vise (preferably an action block)
An armorer's wrench for the barrel nut and flash suppressor
Hi-temp grease for the barrel nut
1/2" drive (preferably a torque wrench)
Roll pin punches
Little hammer for the pin punches (preferably brass hammer)
Vise grips can come in handy
A calibrated eyeball
I think that's it.