M70 Rebarrel questions

Boomer454

Boomer454

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I have a Winchester Model 70 Classic Left handed action.
I found a Win M70. Push feed barrel.
Can this be fitted to my Lh, controlled round feed action? Or is the fitting required too much to make it worth while?

Also. My action is stainless while this barrel is blued. Can either be finished to match the other?
 
It can certainly be done, I'm not sure if the cost will be worthwhile to you. Your barrel will have to be fit to your receiver, and then have an extractor slot cut in it. It will probably have to be shortened a bit on the shank and rechambered for everything to work properly. You can have the barrel electroless nickle plated to attempt to match the stainless (hard to do) or have the receiver blackened to try and match the barrel (even harder to do), or go with something like Armacoat or maybe Teflon coating. Or just live with the two tone look, I have it on a few rifles and think it looks fine. - dan
 
Boomer454 said:
I have a Winchester Model 70 Classic Left handed action.
I found a Win M70. Push feed barrel.
Can this be fitted to my Lh, controlled round feed action? Or is the fitting required too much to make it worth while?

Also. My action is stainless while this barrel is blued. Can either be finished to match the other?
Click to expand...

If the barrel indexes, headspaces correctly, then only extractor groove would have to be cut, and put on, maybe $50. But that usually does not happen that easily, and modifying to fit could cost up to $200. Then you would have a c-m barrel on stainless action and barrel could be left in white, but have to be looked after to prevent rust. Or all could be coated with some sort.
I would rather start with a stainless blank.
 
A push feed barrel is flat faced, a crf barrel face is coned. It would take a bit of work to adapt the barrel.
 
you can actually install a PF barrel on a CRF, and leave it flat faced. I've seen pre-64's and Classics re-barreled without the cone, though it is not something I'd want.

If you find a take-off CRF barrel, it doesn;t have to be a leftie, you just install a right hand barrel upside down (letters down)
 
never could understand the need for the coned breech and the extractor cut...watch the round when fed into the chamber...it doesn't even go near the cone...and Ruger 77's are controlled feed without an extractor cut....strange stuff that coned breech and extractor cut...
 
Rembo said:
never could understand the need for the coned breech and the extractor cut...watch the round when fed into the chamber...it doesn't even go near the cone...and Ruger 77's are controlled feed without an extractor cut....strange stuff that coned breech and extractor cut...
Click to expand...

Rembo, if you take a look at the boltface of a M70 CRF action or a Pre 64 M70 you will see that the bolt is cone shaped, the left lug is and the right side is of coarse occupied by the extractor which projects further than the bolt body hence the need for the extractor cut into the barrel. You could finish off the rear of the barrel flat but this would allow too much of the case head to be unsuported due to the extractor clearance required and this is not as safe as having the barrel coned and the bolt fitted as closely as possible to the barrel therby providing maximum support to the case, it is also vastly better to have this cone in order to guide any round that comes off a little canted from the rails, the Mauser 98 has the exact same cone shape and it has been this way for over 100 years! Can't argue with that, Paul Mauser tried to perfect every aspect of his action. It's another one of those features that you will probably never need but you it's good to have when things go astray just like that big mauser extractor and CRF.
bigbull
 
so how much of the case is left unsupported on a Ruger M77 controlled feed rifle?.
The distance from the bolt face to the edge of the chamber is roughly the same.

Whether you have a flat face or a cone you are starting from the same point of the chamber.

I just measured a Ruger M77 Mark II,...the bolt face is .125 deep, so, for the sake of discussion let's assume .010 clearance between the end of the bolt and the end of the barrel. When I rebarrel a rifle I set this at about .005 but the factory always leaves more clearance. So again, for the sake of discussion let's assume we are dealing with a belted mag chamber. So when the bolt is closed there will be about .220" from the bolt face to the belt shoulder in the chamber. So, we have .125 plus our .010 clearance which is .135 subtracted from .220 equals .085"...this will be the depth of the belt recess in the chamber. So if we taper from the edge of this belt recess at the end of the barrel out to the barrel thread and taper the end of the bolt to match where does the extra cartridge support come from? If there is any extra cartridge supprt on a M70 controlled feed rifle it will not be 360 degrees.
 
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Mauser 98 does not have a coned barrel face.
The M70 coned breech can be traced back to the '03 Springfield, which was a second rate copy of the Mauser. The '03 breeching is inferior to the '98's.
A bolt from a coned breech rifle can be used with a flat faced barrel - the Parker Hale Midland series of rifles are like this. Don't know if this is much of a recommendation, though. It really looks as if there is a lot of case hanging out in the open air, although the acutal projection of the casehead doesn't change, coned breech or flat faced. There is next to nothing surrounding and supporting the boltnose, though.
 
tiriaq said:
Mauser 98 does not have a coned barrel face.
The M70 coned breech can be traced back to the '03 Springfield, which was a second rate copy of the Mauser. The '03 breeching is inferior to the '98's.
A bolt from a coned breech rifle can be used with a flat faced barrel - the Parker Hale Midland series of rifles are like this. Don't know if this is much of a recommendation, though. It really looks as if there is a lot of case hanging out in the open air, although the acutal projection of the casehead doesn't change, coned breech or flat faced. There is next to nothing surrounding and supporting the boltnose, though.
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Sorry tiriaq but your statement is not correct( kinda), if you examine the breech of a 98 you will clearly see that it is coned, the barrel itself is flat but the "C" ring on a mauser is coned, it is what the barrel is torqued up against and the cutout of the "C" breech serves exactly the same purpose as on the M70 CRF actions it is the clearance cut for the extractor, this is all part of the breeching system. The purpose of the extractor cut is to allow the bolt to fit closely to the rear of the barrel therefore the cut is required in order to reduce to a minimum the case projection. In actions that do not have the extractor cut the extractor defines the case head unsuported section, so yes the cut allows the bolt to be fitted more closely to the rear of the barrel and the cone aids in feeding. There are some great pictures of sectioned M98 actions in Jerry Kunhaussens book that clarifies the inner workings of the Mauser 98, and the cone is very visible. As far as the bolt nose there should be nothing supporting this, it can be seen clearly in the Rem M700 & 788, the rear of the barrel is recessed for the bolt head but there are clearances everywhere to prevent contact of any kind, so there is no support. The only actions that support the bolt "nose" are the ones where the bolt locks up directly into the rear of the barrel like a Browning BLR or Sauer 202 for example. Hope this clarifies things.

bigbull
 
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The discussion was about the use of a flat faced barrel with a bolt intended for a coned face breech. Of course the inner collar of the Mauser M98 receiver is part of the Mauser's superior breeching system - but this is irrevevant if the receiver in question is a Model 70. The casehead projection in the Mauser system is less than in the Winchester/Springfield - another example of the superiority of the Mauser. Less brass unsupported. Have a look at a Midland for what happens to breeching when a coned bolt is matched with a flat faced barrel, with no inner collar involved. This is hardly a breeching system worth duplicating by fitting a M70 pushfeed barrel to a M70 originally intended to have a cone faced breech. The very last PH Mauser based actions also did away with the inner collar, thereby reducing the effectiveness of the Mauser designed breech.
There Remington barrel's counterbore does not make contact with the boltnose under normal circumstances. But in the event of a catastrophic case failure, it can provide support. The bolt will be ruined in the process, but containment is not compromised. Teh 700 was able to enhance safety breeching over the Mauser with its collar by doing away with the external extractor and its corresponding cut. The 700 also increased the amount of casehead projection, relative to the Mauser.
 
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The threaded tenon on the push feed barrel is long enough to allow a certain amount of cone but the chamber would have to be deepened. If one wanted to not ream the chamber at all, he would have to machine a spacer to fit between the barrel and receiver. The cartridge protrusion would probably be sufficient.
A mauser without the C-ring but with the breech end of the barrel counterbored to accept the bolt, would likely be as strong and safe as one with the ring. The Japanese Arisake used this sort of breeching system. I kind of like the inner collar (or C-ring) but, in some respects, the counterbored barrel might be as good or better.
I have fitted barrels for myself to pre-64 actions without coning the breech or cutting the extractor cut and have felt surprisingly secure behind the rifle though I knew it wasn't really right. Nonetheless, I prefer to cone the breech and make the extractor cut as is proper.
To use this push feed barrel, the right way would be to cone the breech and make the extractor cut then deepen the chamber to achieve the appropriate headspace. Figure on about 150 bucks. Regards, Bill.
 
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