I started with a female/female 5/16 couplers and some 5/16 threaded rod from Home Depot. I only use about 1.5 inches fo rod. I put both couplers on the rod.. screwing each one on from the opposite end until they met in the middle and snugged up.
I put the rivet through the rail and in the receiver and then installed the couplers. I just loosened both the couplers until they pushed out against the opposite side of the rail and the the rivet. I put a lot of tension to make sure that the rails weren't to close and it wouldn't bind the bolt.
Next, I cut the protruding rivet shaft almost in half (I left just a hair longer than half left). Once I got the rivet cut off, I got the TIG welder (Harbor Freight special) ready. I set the heat level at about 5 and sparked up on the rivet. I just slowly pushed and pulled back on the rivet and until it mushroomed down to the receiver. While it was still molten, I hit it with a rivet shaper and a BFH.
I let them all cool before removing the coupler so if there was any shrinkage, it would pull the rail closer to the receiver. I had to use the dremel to give straight edges the rivet heads on the inside of the rails so the bolt would clear.
So.. the bolt slides all the way down to the barrel with zero "hang" spots and the melted rivets look just like they were crushed by a press.
I left the couplers at the shop so I can't take pics of it and I am heading out the MGshooters.com desert shoot tomorrow and the 42 is already packed away. I will update with pics of the coupler if anybody has interest when I get back.
thanks,
Ron
