Spanky, possibly you should re read my post. All I said I did, is to deburr and break the edge to get a better lockup. I did NOT remove any material, other than what should not have been there in the first place. When I initially checked the engagement, it was about the .015 wide, due to the fact their was a sharp edge on the shelf that it was riding on. If it had fit with this kind of edge, along with the burrs, I think I would have been chasing fliers, for as long as I owned the gun. Had I worked on the underlug to get it to close, It would have closed, just like my factory fitted barrels on my other frame, but again, the breach face is riding on a bunch of divets and ridges left from the factory saw cut and the way the barrel was banged around before the install. FYI, I bought the gun that the barrel was on, so I know the history of the barrel, "it is a shooter" in a low intensity HM2. My entire point of posting what I found is to possibly give folks another avenue, than just going straight to where you need to go,"the underlug" , to remove metal and looking at the breach face and the barrel face first. Perhaps if the end of the barrel was lathe turned first, instead of the saw cut, the precision barrel fit could be had without as much hand fitting. I think that everyone would be wise to first stone down the barrel face, and the breach face before fitting, and I believe, there would be a heck of alot less need to even touch the pivot, and great deal more accuracy attained by the quality of fitment. The more surface area actually touching and the more even the breach to barrel fit the more potential accuracy of the gun. I am not talking about mass material removal, but by just breaking edges, taking off high spots, their is probably 70% more surface area mating on the two surfaces, due to the fact that before, it is just riding the high spots. The more you shoot the gun without a stoned finish the faster the potential for the barrel face wearing and having to go back and shim it to take out the play, that was created when fitting, as every time you pull the trigger, a few more of the peaks and valleys left in, from the manufacturing process, will peen down, making for a looser fit. The fewer vibrations set off every time you pull the trigger, the more potential accuracy of the gun. All I used was a couple of stones from Brownells, a tube of blue made by Permatex for checking backlash, and valve jobs ect. Had I started out with the stoning,"just to deburr and break edges" , I would not have spent 3 minutes to fit the barrel, which fits many times tighter than a factory fit barrel. Again , Thanks to Larry for the insight .
