1" - 16tpi. No cone on the Montana as it has a "Mauser collar". The 'cone' is built into the Mauser collar (on the Montana). I have a Tikka LSA55 that uses 1"-16tpi, also. The post 64 Winchester 70 push feed has a flat breech and uses 1" x 16tpi, like the Montana. The post 64 Win 70 'Classic' is coned as is the pre 64 70. As for the length of the threads, don't know or remember. Probably not the same for a "drop-in".
Posts: 719 | Location: fly over America, also known as Oklahoma | Registered: 02 June 2013
What barrel? I have a couple of Montana actions I've had for years and never got around to building anything on them. Even have a stock for one. Keep thinking I'll build my son a 6.5 CM with it. Have stock, barrel, action, just need ambition.