Home Forums Hunting & Shooting Gunsmithing M70 Long Range Rebarrel

I have a Winchester M70 Long Range (new name for Coyote light?) in 6.5 PRC that is getting close to a rebarrel and was considering my options. My wife got it for me NIB a few years ago for an elk hunt that never happened. It never shot as great but I shot it just the same and its definitely degrading as I am approaching the 1000 round mark. I certainly like the rifle (have two other M70s).l but it's reaching decision time.

I see that McGowan, PacNor, and Lothar Walther will sell you a pre-fit with/out the extractor cut(own a bench-top mill so this isn't a totally foreign to me). Does anyone know how good/terrible these are? Seems my options are sell it, diy on a pre-fit, or find a smith (haven't found an option in GA). Open to all opinions.

Those are all good makers. I would assume M70 Win threads would be pretty consistent. Mauser 98 prefit barrels are a waste. There is so much variation that the threads are too loose. Anything made to fit everything actually fits nothing.

You just can't get a good tight tolerance fit on pre-fit, too much of a range in tolerance on thousands of barrel vs thousands of pre-fit. Get a blank and have it custom fit to your action.

So, how many "gunsmiths today look up barrel dimensions, machine to those specs and stick the barrel on!

Only the ones that don't know how to "thread to fit". A basic machine shop practice learned back when you were probably still in diapers.

None that I would use.

Well, I’ll just bet mine would not — and did not. 😉

This is a later model New Haven Model 70 that I removed the barrel from prior to some bedding and stock work. The receiver threads are just nasty. Winchester threads the receivers and then broaches the raceway for the lugs the full length of the receiver. Some of the threads have been torn out by the broaching process.


The action screw threads are done using a plug tap. A plug style tap doesn't cut threads...it displaces material to form the threads. Well, common sense tells us that material has to go somewhere. As long as the area is then remachined to address the changes from the plug tapping process, all is good. But that doesn't happen at Winny World.

After I did a light lapping pass, the raised areas at 90 degrees from the plug tapped hole are very apparent. It took somewhere from .008-.010 to straighten this out.


All in all...a typical day at Winchester.

If a post 64 and not a Classic model or other control feed model. The Win 70 should be a push feed and should not require a cone breach. You did not include a photo of the bolt and receiver area, so can not tell by the OP.
But would suggest if it is a push feed to get a LW SS Magnum Sporter in 1-8 and have it threaded and chambered, headspace for your rifle/cartridge.

If you are concerned about the receiver threads ask about a M-70 receiver truing mandrel and have the receiver face and threads trued, lugs lapped to 100%, bolt face squared and it should shoot like a house on fire when put together and properly crowned.

This the “new” one Al?

If so … you work fast!

Pac-Nor

https://pac-nor.com/

My gun is definitely CRF. The barrel says Portugal, so maybe they aren't as sloppy with the broaching. If my receiver threads looked like what Al_Nyhus posted...I would probably start over with a new gun/receiver. Yikes.

Any recommendations on a Smith? I am in northeast Georgia?

Winchester changed the thread dimensions when they ran into a problem with chamber distortion, especially in WSM chamberings, due to the poorly fitting, interrupted threads. The new threads are 1 1/16 by 28TPI. This makes them larger then the diameter of the locking lug raceways. The interrupted thread has been an issue since 1964, whether in push feeds or CRF. When re-barreling a New Haven Model 70 in one of the WSM's, I always re-threaded to 1 1/16 diameter.
As far as cutting to specs is concerned, there is absolutely nothing wrong with that, providing the specs are accurate. A vee thread doesn't have to be tight, there are accepted tolerances for headspace, and machining on the barrel stands alone. When I was doing a lot of repeat barrel work, I recorded headspace dimensions and thread pitch and pitch diameter for each action so I could duplicate barrels without having the rifle in the shop. I'm sure that some of the 'smiths who are using CNC equipment for fitting and chambering are doing the same thing via their programming.
The other thing I have to mention; the threads on the later Model 70's, like yours, are more precisely cut than on the New Haven guns. Given the fine thread pitch, the tolerance has to be closer.
Having said all this, I still believe, like JKob, you get the best result by having a competent 'smith fit a custom barrel for you. GD

No, this is a laminated 270WSM. As nasty as the threads are, they cleaned up ok with just a little lapping. Then the shoulder and receiver face had very good contact....it came up to 'tight' instantly. After pillar bedding (with the center screw mod), it shoots pretty well.

Good shootin' -Al

Thank you, this is helpful