Brand new, more or less, Mauser M-48 Czech whatever. I think these are post WWII captures and re-arsenals.

I think short bolt, large ring.

Use the bolt/receiver, new trigger, barrel, furniture. Re-barrel in 45/70 Govt.

Drill and tap for a scope. What else do I need to do? I'm entirely new to building from a Mauser action.

I have a 38/22 also. Nice shape. Would this be a better action/receiver? I like this gun, and don't really want to take it apart.

You will have some serious boltface modification to do. Magazine follower modifications also, due to the large rim diameter on the 45-70. This conversion is usually better suited to an Enfield or Siamese Mauser.

This would made a dandy single shot for you.

You could try and make it a repeater, but since the M48 was purposely designed to feed the 8x57JS (rimless) cartridge flawlessly, to make the rifle feed more than one at a time would be a pretty good engineering project.

I would humbly suggest looking at the 450 Marlin. 47/70 performance in a belted case that'll feed much easier through a bolt gun.

Another suggestion is a Mosin Nagant. Yup, these are very strong actions and the only thing you'd have to do is rebarrel, open up the feed rails, and open up the front of the magazine by making it wider. The bolt will work as is. Makes a dandy 45-70. So does the No3 and No4 Smle 303 Britishs.

Single shot.. sure... repeater? you can't adapt a siamese or rigby box to it.. feeding will be a nightmare.. i've seen huskys that were single shoot...

buy a siamese...

jeffe

The only Mauser suitable for conversion to the 45-70 (and other rounds with similar rim diameters) is the Siamese.

OK,

I have a Mosin in the safe, 91/30. The Mauser bolt just seems a better design.

Have a single shot -- Ruger No. 1 in 45/70. There's a Marlin 1895 calling my name, in 45/70. But bullet weight is really limited in the Marlin lever action.

Mauser style bolt in this cal. seems like a good idea.

I you just gotta have a project rifle in 45-70 you might consider a British military Enfield of the SMLE variety. It's doable. A couple of guys who post here (I think) have done it or have had one done. I know at one time Gibbs Rifle Co. was offering an SMLE conversion in 45-70. Do a search and you'll probably find more info.