Clymer and the other guy will make the backbore reamers. Chamber reamers, they stock. Another way to go for a backbore reamer: you can buy a 1/4"/ft taper pin reamer of the appropriate dia, have the o.d. spin ground (no clearance, as reamers have no o.d. clearance) to the dia you want. The taper will form the choke cone. Then either have that reamer piloted for a bushing or take a regular chucking reamer and have it piloted for a bushing. Of course you'll need them reduced for extentions and the extensions themselves, etc.. If you have to pay for all this grinding, you'll be a small pile of $100 bills into it.
For a lap, I like a split copper bar.
Let me know if you're still interested in the Ithaca.
Last edited by Chuck H; 01/26/11 08:15 AM.
