Shotgun Muzzle Diameter For Threaded Chokes

[88 man]

Just wondering if anyone knows what the muzzle dia needs to be to be able to thread for choke tubes.I've got a Win 1200 full choke barrel that I'd like threaded for winchokes if the muzzle is thick enough.I've got lots of choke tubes so just need it threaded if possible.The barrel has a factory 3" chamber so I'm thinking winchokes were around when this shotgun was made.
Thanks !

 

[guntech]

Barrels are measured by the installer before they will do it... sometimes the inside isn't small enough, sometimes the outside isn't large enough... Find someone who does choke tubes and let them measure/do it.

 

[remp49]

For 12 ga. Winchokes you need a min. outside dia. of .845". The bore can be a max. dia. of .735".

 

[88 man]

Thanks.Now I've got to find my micrometres !