7400 Owners
Well, I have always complained that my 7400 would change POI all the time depending the screw on the forarm and how hard its tightened down. Well, I finally decided to see if I can do anything about it. The gun shoots well and never jams. I have had it for almost 16 years now.
Ok, well first, my forearm is synthetic since I busted my old stock. Anyway, if you take your forarm screw out, you will see that the forearem is firmly pushing against the action but the screw screws into the barrel/gas port and on my gun a gap between the front of the forearm and the gas port/screw hole. Well what happens is the tighter the screw, it pulls the barrel and the looser well you know.
So to test this, I put a small spacer kit between the gasport/screw hole/barrel assembly and the forearm. I did this just enough so you was not pulling or pushing the barrel anymore but the back of the forearm was not pushing against the action any more. I just added enough spacers to where when you tightened the screw its independent of how tight you do it.
Well, it worked. I went to the range and loosened the forearm screw and shot 1.5" group with handloads then did the same with the screw tight as you can get it. Only thing is basically your forearm is totally connected to the barrel/gas port assemply and putting unneessesary force up or down is going to affect things (not sure how you would do that anyway).
What I plan to do instead of spaces is take a dremel tool and cut out part of the forearm or put some glass in the front.