threading rimfire action

[robbor]

What is the proper way to set up and action for threading.
I want to try and thread my marlin single shot action and add a barrel. Also bolt head truing.Im guessing on the bolt head all that needs to be done would be to mill the head flat perpendicular to the bolt body? Thanks

 

[sjk]

Just make sure the action is held or fixtured so that it is in alignment with the bore line and runs concentric and is good and tight so it won't come loose during threading. If you don't have thread mics then you can use the 3 wires and a plug gage, if not the barrel itself will be the gage if you have it handy. Set the compound at 29.5 degrees and go to it and end the threads in a groove corresponding to the threading dial. It's not hard, but every action is different especially if it is not a rounded OD. Some do this with the use of a tap in the tailstock, but when the ID is larger than .500 I tend to shy away from this process as it takes out a lot of stock all at once. If not set up right, things can go wrong. Also check the head with a set up taper to see if the lathe itself does not run out. I have seen this happen on some,many)chinese,sic) lathes and they pulled their hair out when the thing shot off the bore line. It had to be re adjusted to make the threads aligned. It's quite a tedious job. Lots of luck