I timed myself cutting and crowning a factory takeoff barrel I spun on a vanguard this afternoon. Just for kicks.
The 4 jaw was already on the lathe, a grizzly gunsmith lathe, the medium sized one. Tape barrel and wrap a sheet of brass over the tape under the jaws. Inserted barrel through headstock and dial ID of bore to .0005, use spider to dial the shank in on the backside. Used parting tool to cut to length, the right one. Square up with carbide tool. Use solid carbide boring bar choked up in tool holder to cut 11 degree crown, change angle and chamfer edge of the bore and use backside of the cutter to break the edge of the OD. Bump lathe up to 1000rpm and polish the toolmarks out of the crown. Loosen jaws and remove barrel. Check clock.
Verdict 18minutes. I need to go to work for that guy on commission, I'd be rolling in $$$$
