[wireless]

I have a machinist buddy who is going to thread a 10/22 barrel for me (for free:D ). I know it needs to be 1/2 x 28tpi, but how far back does it need to be threaded? Will the average machinist know how to thread it concentric to the bore and not the outer barrel surface? Will I need to have it recrowned afterwards? He doesn't do any firearm related machining, so I would like to be able to offer up some of this info in case he asks. It is only a junker barrel, but I would like to get it right the first time. Any help or advice would be appreciated. Thanks!

[Riss]

Threads should be by the "bbok" literallt. Use the specs found in the manual. Threads should be at least 1/2" long, 5/8 " is better. uncercut at root of threads. Then you need to figure out if you need a shuared shoulder or a 45 deg. chamfer at base end of threads. Turning concentric to bore can be done with a plug gauge that just enters the threads. Gauges usually come in dimensions by the thousandths. Use the one that just fits in the bore. He should then center the barrel against that. Centering should be "dead nuts". No movement or runout of the indicator.

[Watchman]

5/8's of an inch back from the muzzle. An 1/8" undercut made by a standard cutoff tool will be fine for the thread relief.

He will need t o put the tailstock center in the bore. That will make the bore run concentric to the threads.

The big thing is turn turn the threads on the lathe, dont use a die as it will not be straight enough. Once the threads are cut, a standard 45 degree chamfer on the lead thread will keep it from getting dinged up.

I would recrown the barrel with an 11 degree target crown. Its not a big deal, any machinist should be more than capable of doing it. Unless a 3 jaw chuck is adjustable for runout, a 4 jaw chuck is highly reccomended, to get it dead nuts as Riss mentioned.

When crowning, be sure to run the feed from the bore out to the major diameter. This will keep any burrs to a minimum.