I use two very thin pieces of dense cardboard, like the backing from legal pads, cut to fit my 4 inch vise jaws. The jaws of my vise are relatively smooth with only a slight texture. Remove the grip and clamp the flat sides of the grip boss. You can get the vise jaw flush against the top edge and very close to the forward edge of the boss. It can be clamped very tight as this area is very solid. That gives you plenty of room to work around the castle nut with no interference of the receiver end-plate, castle nut or receiver ext. tube. The cardboard prevents damage to the finish. This method allows me to apply some serious torque to remove very tight nuts and gives very good feedback when tightening.
Billy
US Army Retired, NRA Life member, M/C mechanic, Gunsmith
Bookmarks