The buffer is kinda easy to do. I get mine and the rivets at SARCO. Pry the old one off. Use a taper reamer, the long kind, not the 45 degree one, and lightly open on both sides. Place it over the existing rivet. I use a piece of round dowel like a broom handle through the front of the receiver. Tap this lightly to see where the rivet contacts the back side. Open it up with the reamer a little more to the rivet side. If the rivet has a decided edge to one side then you may be able to lightly file the rivet. If not open the hole a little more to the side you need clearance on. Now you take your dowel and drill a hole in the end of it to go over the rivet. Not bigger than 1/4" diameter. Put the buffer in, put the dowel over it and smack it with a hammer. 16 oz hammer is okay. If you want you can put Acra Glass gel mixture in to help hold it or Poly Choke rib holding glue. Any glue that doesn't get glass hard. Even silicon gasket sealer as it doesn't react to solvents like other glues. There you are done. If you don't do this the bolt handle can travel back and dent the slot in the receiver on the bolt handle way. Also, the bolt can crack then you are in for it. I have a barrel extension that I use to line things up and do this with some other home made tools. Also, Roy Dunlap covers this in his excellent book on gunsmithing. By the way I have never had to replace a rivet, yet..........
You can get a lot of combinations with friction system. Basic for heavy is recoil spring in place and shotgun in vertical (up) position: solid ring with bevel (inside bevel) to the top. If you have the old friction ring then the the taper on the exterior goes down facing the spring. Then put the bronze/brass friction piece on with the bevel to the top as this fits in the barrel lug. Lighter loads you move the friction ring between the receiver and recoil spring with the bevel facing the receiver.
You can also play around with a magnum or standard spring from an A5 or you can go to the 15 coil Rem. spring. You can play around with the magnum A5 friction pieces also. Just go heavy and then lighten them up. Remington springs are all flat or square coil and have 15 or 20 coils, both work. If you hear the action you may have the 15 coil spring and should go to the 20 coil or the A5 standard spring. If the barrel locks up with this spring then you need to run a friction ring between the receiver and spring in addition to one on the other end. I have a lot of play time with the Rem. 11 and the A5.
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