Picked up an early model 7 in 260 Remington what are my options as far as scope bases for the 3 hole receiver and what twist barrel should it be. I'm really hoping it will stabilize the 100gr partition.

Leupold one piece base is what mine had on it. And yes on stabilizing 100gr Partitions. Mine was one of the very first 260s produced and it shot fine with 120 Ballistic tips and numerous 140s, all of which would be longer than 100gr Partitions.

Years after when I ended up with another early M7 with only 3 base holes I simply chucked it in the mill and drilled and tapped the 4th hole. Easy job that opens up a bunch of mounting options.

There are a lot of 1 piece pic rails that will work as well as DNZ 1 piece bases...these have a 4th hole you could have drilled/tapped later like TheKid mentions. I have several Talley pic rails I'm not using, if you're interested I'll cut you a deal on one, just send me a pm.

Is adding a second hole in the rear bridge a fairly simple job? I'm contemplating having this done in the future and an squeamish about letting any local smiths do it.

I would love an old M7 with the walnut stock and 18 1/2" barrel. I know this has nothing to do with the topic, but there it is.

I had an old taxidermist friend that killed a hell of a lot of deer with the above in 243.

It’s about as simple a gunsmithing job as there is. The way I do it is to put a base on the front ring, 700 base will work. Level receiver using the base in both axis. Locate the rear bridge hole and set zero. Move over the required amount to get to where the new hole goes. Center drill then drill and tap a 6x48 through hole. Deburr and you’re done.

I appreciate the response and apologize to 100grNP for stepping on his thread.

It sounds fairly straightforward, but definitely beyond what I have for tools. I'll have to hope for an honest smith in my area if I choose to move forward with this project.

Thanks again.