dreadpirate Wrote:Easy - heat the barrel nut with a torch so the Loctite flows out and settles in the gaps after you have it assembled. Use Loctite 620 which should not liquefy under normal shooting temperatures.
Heat it with a torch? To be clear, you mean a naked flame? No, heating aluminium brings with it the potential of annealing. There has to be a better way.
Why don't you coat the inside of the receiver with glue and not the outside of the barrel extension? Then as the two parts are brought together it pushes the excess in the opposite direction of the face. Hopefully the receiver face and shoulder remains clean. It would be a little more fiddly cleaning the excess but there's enough access into the receiver to do this.
Screw the barrel nut on and leave it vertical with the barrel pointing down. Gravity keeps the liquid glue right up to but not on the face as it hardens.