I have a Montana with an 'o6 boltface.. Thinking about converting it to a magnum. I know it will need a new magazine box as the current one has a small spacer in the rear. Probably will need a new follower too. And will need to either work on the extractor or get another. My only other concern is the feed rails. Wanting to do a .375H&H.
Do you guys think it will feed reliable as is or will I need to work the rails a bit ? Any learned opinions on this conversion ?
Thanks,

Hey Rancher,
I have not looked at a magnum closely (all the ones I have are standard boltface) but I doubt that any change would be necessary beyond changing the box and follower. Not even real sure on the follower. Like the new M70, the 1999s magazine box forms most of the feed rails. If you already have another in a magnum bolt, just take some measurements to see what difference if any. Alternatively, give the boys in Kalispell a call and see what they have to say. Then let me know! Regards, Bill.

If you want to use a .375 H&H length cartridge, you'll most likely have to get a different ejector as well - minor modification. At least this is the case if wanting to go to a full length cartridge in a M70.
- mike

If it is an unused action why don't you contact Montana rifle company and ask about exchanging it? This would sure be easier than doing all the changes.

Second the last post. Why go to all that work when you could sell the action, probably at or close to what you paid for it, and buy an action already set up like you want it?