thread size 340 savage?

What is the thread size for a 340 Savage rifle? Are barrels available, needing 225 Winchester?
THANKS

From NRA Gunsmithing Guide ----- Savage m340 et al = .850 dia. 18v tpi
I found this on the internet, so take it with a grain of salt... I do know that they are a smaller diameter though. The nut is different too. Numrich has barrels on occasion, usually .30-30 though.

I can finally finalize this! The threads on my savage 340 .223 rem, measure .864" x 18tpi. - I assume that is undersized for a 7/8" shank. Be aware that those are the threads on the barrel. Enough of a difference that I wouldn't want .025" play if the receiver is .875 and the barrel is .850 like the NRA guide says... Just posting this in case anyone is looking for better info.

Machinery's Handbook gives the following for a 7/8-18 UNS Class 2A thread

External thread Major diameter .8736 maximum and .8649 minimum
External thread Pitch diameter .8375 maximum and .8329 minimum.

Internal thread Class 2B:
Internal thread Minor diameter .815 minimum and .828 maximum
Internal thread Pitch diameter .8389 minimum and .8449 maximum
Major diameter internal thread .8750

A spare barrel I have in stock also measures .864 major diameter.

What you really care about is the pitch diameter. To mike that you need thread wires, which I don't have either. (The crest diameter can be small, and yet the pitch diameter still be in the middle of tolerance.)

Now to find out what the action threads really are. For that a precision ground thread gage is needed. Large $$ for us hobbyists.