Upper Receiver Vise Block

thingiverse

This is an upper receiver vise block for an AR15. The bottom square can be put into a vise so you can properly torque a barrel or handguard. The vise block has vertical holes in it. It was designed to put in a 3/8 shaft in there for support for torquing. But I ended up putting in 3/8 bolts into the holes. I am convinced I would have damaged the upper receiver before this broke. Also there are recessed/threaded holes running horizontally so you can tighten the vise as much as you need without damaging the vise block. Use 1/4" by 1" (20 TPI) bolts will sit in there perfectly even. The 3/8 bolts I have in there are only 2.5" long, so that's why they look short. I used NylonX, but I imagine it would be plenty strong with PETG or ABS, with the bolts in it. TL;DR Strong AR upper receiver vise block. Use 3/8" x 3" bolts in the vertical holes (bolt head at bottom) Use 1/4" x 1" (20 TPI) in horizontal holes Probably will need to clean up 1/4 x 20TPI holes with a tap, or screw before threading all the way in I was wearing slippers in the pictures