Cut and Crown a Nitrided Barrel?

[Stumpy1]

Hi All,

I was wondering what your thoughts were on cutting and crowning a nitrided barrel? I need to remove the threaded portion of a barrel. The barrel is a CMMG rimfire, and the crown would be done using the Manson crowning tool. I know I need to get through the surface, and will do so with a cutoff wheel, but after that would use the Manson.

Thoughts? Ideas? Stop! Don't do it!!

Thanks In Advance!

Stumpy

 

[gunsandgunsmithing]

The surface of the bore is also hard, from end to end. So wherever you re crown, it'll still be hard where it matters most, at the circumference of the bore. I'd set it up in a lathe, indicated in, and grind the crown with a fashioned tool post grinder, rather than cut it with carbide or hss.
FWIW.---Mike

 

[Stumpy1]

Thanks! That is kinda what I thought. I might just abandon the idea of the cutoff, and instead suggest a pinned brake of some sort. Too bad we can't leave stuff like this alone in all the states...

Thanks Again,

Frank

 

[Scott Harris]

The melonite is only a few microns thick....should be really easy to cut through with a parting blade. Part off the old crown and it should be not problem to recrown it since you will have exposed non-melonited surface.