Well, like the title says, I am making progress... slow but progress.
My rifling machine (I use the term loosely) is finished or at least the prototype is finished. It is a modern take on the old style wooden rifling benches but smaller and made of steel. I will post some photos after I neaten it up some.
In any case, it works! I started rifling a piece of 3/4" pipe as a trial run. I learned a few things and I believe I will modify the rifling head.
I used the old style wooden rifling head with inletted cutter. Not going as well as it might though it does work. The cutter is a slip fit into the inletted head and I used paper shims to raise the cutter but it keeps coming loose so I think I will change the design slightly and add a shoe under the cutting head then shim the shoe.
In any case, the goal was deep wide grooves and narrow lands. My trial run on 3/4" pipe has turned out not bad though rifling is probably only about 1/2 depth right now. Grooves are about twice as wide as lands. I may take it all the way as I am still learning so I might as well learn on pipe.
After I practice a bit then modify the cutter head I will pick up some 4140 to make choke tube, barrel adapter and muzzle break.
I have to say that dragging a rifling cutter through a barrel (short as it is) is work! Not sure how many strokes I have done but I was running from 25 to 100 strokes per groove (depending on cutter "bite") then re-shimming and run around again. So far I have used about 15 paper shims so LOTS of strokes and still only half there.
I may modify the cutter some too. I think it has too much surface contact so fewer teeth should increase cutting edge pressure and metal removal ~ and work, but less strokes.
Longbow