I'm trying to make a cheap and simple rifling bench. I may only do 1 or 2 barrels with it.
Today I made a 6 foot long 1/2" square steel bar, twisted to 1 turn in 60". 2 v-groove bearings will be bolted opposite each other to capture the twisted bar, and make it turn as it is pulled through them.
I'll make a conventional rod and hickory cutter holder, and use .100" thick power hacksaw blade pieces for a cutter.
The hard part will be indexing the cutter rod for 7 grooves. I'm thinking of making a 2" diameter collar that is attached to the end of the twisted bar, and is bored to accept a 1" plug that holds the cutter rod. I could drill 7 holes, evenly spaced around the 2" collar. The 1" plug would have an indent that would be turned for each groove.
Comments? Would a system that required loosening a set screw, then turning the rod plug, then tightening the set screw, be too much trouble? Is it possible to cut each groove to a finished depth before indexing?