Seems like I'm always trying to help out a friend... I have a 98 mauser Large thread barrel in 6.5x55 that's never been used. A friend is considering a new barrel for his post 64' push feed model 70. I am not a machinist so here is a question for you guys.

Can the existing Mauser threads be carefully turned off and the shank recut for model 70 threads? What I'm seeing is LR Mauser threads are 1.100 and the model 70 is 1.000. Is that enough difference to clean up the Mauser threads or will the shank end up undersized?

Probably easier and more cost efficient to start with a new barrel, just trying to help a friend out. Thanks for the input.

If you turn off the 12 tpi, 1.1 threads down to a 1 inch shank, (Mauser used English system for these, not Metric as some think) some of the bottoms of the old thread will still be visible depending on how sloppy the original threads were. Many after marked Mauser threads are loose; but they are very forgiving. Of course the new threads will be 16 TPI. Your new threads will not have perfectly clean tops, or they will clean up at somewhat smaller than one inch.
I have done it for myself.
Not saying you should do it; never do anything I say.

Ok, well that answers my original questions. Now here is another one. If the tops of the new cut model 70 threads are not clean, what sort of issue (if any) might that cause ?

Thanks!

None. Depending on how flat you are talking about. Threads and their shape and engagement, class of fit, etc, are a whole course in and of itself.
Many threads have flat tops, in varying degrees. Not degrees of angle.
Let's put it this way; no professional gunsmith will do what you suggest.
Most machinists, would.

A threaded/chambered mauser barrel is worth more than a new blank if it's in a decent sporter contour. Military, not quite so much.

I'd sell the mauser barrel, or trade for a blank. I think most gunsmiths would rather start from a blank than re-thread/fit one from another rifle with different threads/dimensions.

What contour is your barrel?

Thanks for the info dpcd. I didn't want to give up my Mauser barrel anyway!

My friend got on a kick a year or three ago about this same rifle. It's a post 64' push feed model 70 in nice shape. The problem is that he's bored with the 270 barrel. He wants to rebarrel/rework the rifle for another cartridge. I told him to look for a clean take off Model 70, Ruger M77, or Ruger No.1 barrel. We both looked for a short time then forgot about it. Last time he was over here, he was asking about a short action Remington 700 for his daughter to shoot deer with. Now that he's bought one of those , he's back on the rebarrel quest....

Anyway, it's nice to have loyal friends.

If he wants to rebarrel and get something different than .270, do something interesting on the rifle. Personally, I'd do a .338-06, .375-06, or 6.5-06.

Arguably, the .270 is one of the best, if not the absolute best choice of all of the possibilities, but building rifles has not a lot to do with the best choice for most of us.

A friend is going through this. He's built a 6.5 creedmoor, wants to build a .25 creedmoor, looking at some long throat snake oil website that calls itself +P Throating (as if that's new, remember Roy Weatherby, Rocky Gibbs, etc, etc). I told him if he'd just rebarreled his .270 to 6.5-06 with a correct twist, he'd be way past all that already. He keeps looking at performance that with similar design bullets, I already have with my .300 mag, .338 mag, and can surpass with a 6.5-06. But, he can move his bolt 1/2" or so less each time, greatly saving in labor while he's shooting. To be fair, his recoil is half of what mine is with the 338.

Well it's different strokes for different folks. I don't try to push my preference off on anyone, and I'm not influenced the least bit by someone else's pet cartridge. Shoot whatever you like. Plenty of cartridge to go around.

I like the 6.5x55 over the Creedmore or the 6.5-06 purely and simply because of it's history, and the nostalgia of classy old rifles. So that's it for me. Others don't give a hoot about being sentimental. Nothing wrong with that. Do what makes you happy and don't worry about what others think.

**I also choose the 6.5x55 because I can't afford a Mannlicher Schoenauer in 6.5x54....yet.

I just yesterday removed a 270 barrel from a 700 and used it as a pry bar; all they are good for. Zero use for a 270 although I have lots of them; for the actions only!
I always try to influence guys on caliber selections because they are usually misguided, misinformed, and often wrong, when they come to me for advice.
They read too much internet stuff.
Tell him to rebarrel it for a 400 Whelen. Although 338-06 is nice.

400 Whelen is the cartridge I don't have. I skipped it, went from .375-06 to .429 express. I like building rifles with '06 based cartridges; lot of performance range there that's overlooked by those looking for newer cartridges. But, I've never gotten into the Gibbs and AI cartridges, just not my preference. I do have one Gibbs, done by Rocky himself.

400 is more versatile due to wider availability of bullets. And it is Improved; has to be to get a good shoulder. I use only the G&H version.

The 400 whelen is a cartridge I've thought about off and on for a long time. I think it was the 2006 Gun Digest that ran a good story about someone building a 400 Whelen (an improved version called the Brown-Whelen actually). He took it to Africa and shot several big game animals with it. Michael Petrov's information on the Double Gun BBS forum about the correct shoulder diameter really cleared up a lot of disinformation. He also had a chapter in Vol. II of his Custom Gunmakers book about building a 400 Whelen. I like the idea of the 400 Whelen, especially for shooting cast boolits. I just have too many others projects in the works for myself right now.

My favorite cartridge is the 30-06. It wasn't my first rifle, but it was the first one I started handloading for. Unlike the .270, I don't think anyone can get bored with a 30-06. There is such a wide range of bullet weights available for it. It's a serious hunting round for whatever you want to hunt. It's easy to load cast boolits for it as well. I can't remember where I read this , but someone once said you can spend your whole life chasing other cartridges up and down the ladder...but you eventually come back to the 30-06 and realize it actually is darn near perfect!

Virtually any barrel can be adapted to any action. Some are just more work than others. Regards, Bill.

Which is exactly why I don't use a 30-06; too common. No fun in that; I want something unique.
Yes, any barrel can be fitted to any action. If the shank is too small, you machine a bushing.
The Germans did that at the bcd (Gustlaf) plant on some Kar98ks; to use the MG13 surplus barrels, they had to do that. I have two of them. Fairly rare.