Winchester model 70 caliber conversion question

Claven2

Claven2

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I've gotten a .30-06 Winchester post-92 classic CRF action (LH model) rebarelled to 7x57.

The problem is that the 7x57 is almost 1.2" shorter than .30-06.

I'm curious if anyone knows which magazine box, follower and bolt stop combination is best for 7x57, and also where to look for the correct parts?

I did pick up a mag box with a longer spacer than the one on my .30-06 box that looks like it might be a more ideal length box for 7x57, but it has no follower, spring or bolt stop with it. This box is marked "AM".

Anyone able to provide some info or help?
 
I'd be surprised if it didn't feed 7x57's as it is...but I assume you have tried it.

I've had a 7x57 in a 700 which has a longer mag box than a M70 in 30-06 and it fed fine,..but the 700 is a push feed...the controlled feed M70 might need tweaking to feed....
 
I've got Rembo's old 7x57 built on a 700 long action. It feeds very smoothly, and with the longer mag box it allows me to seat heavier bullets further out. Try running some 7x57 snap caps or dummy rounds through your Winchester before you change any parts. As far as action length and bolt throw, I've never had any problems with mine, even with the 700 LA, the rifle is just al ittle over 7 1/2 pounds with a scope and full mag.
 
Claven: What bullets and throating does your 7 X 57 have. A quick comparison of my handloads for 7 X 57 and 30-06 with 150 grain and 180 grain respectively show a length difference of only 2/10 of an inch (3.1 and 3.3 approx). Your figure of 1.2" difference doesn't compute for me unless you have a very short throat in the 7 and a lighter and much shorter bullet too.
 
Actually, I'm not sure the current throat length. I just got my pac-nor bbl pre-chambered in 7x57 and headspaced by taking a few thou off the barrel shank's shoulder.

As I said, it DOES feed right now but using winchester factory rounds, there's nearly a 1/2" difference between a 7x57 round and a .30-06 round. That extra half inch would be nice to use to shorten the bolt throw.
 
maybe you should have rechambered the barrel to 7-08AI or 284 Win and put it on a short action then....:D


Claven2 said:
Actually, I'm not sure the current throat length. I just got my pac-nor bbl pre-chambered in 7x57 and headspaced by taking a few thou off the barrel shank's shoulder...That extra half inch would be nice to use to shorten the bolt throw.
Click to expand...
 
If you forsee problems with bursitis in your elbow in the near future, bolt throw might be something to worry about. Otherwise, there are few areas where one half inch makes any difference and I don't think bolt throw is one of them.
Re-chamber to 280 if the thought of the too-long magazine keeps you awake nights. Regards, Bill.
 
Leeper said:
If you forsee problems with bursitis in your elbow in the near future, bolt throw might be something to worry about. Otherwise, there are few areas where one half inch makes any difference and I don't think bolt throw is one of them.
Re-chamber to 280 if the thought of the too-long magazine keeps you awake nights. Regards, Bill.
Click to expand...

wise words.....I would have suggested a 280 Ackley but that might start a controversy.....nah......:D
 
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As much as I like .280, 7x57 is an epic classic. Probably I'm just being anal, but it would be nice to have the mag box and follower that winchester intended for mid-length calibers.

So does nobody know what mag follower and spring go with the "AM" length mag box?
 
First find out how long your throat is. If it is typical of a lot of them it will let you seat handloaded bullets out quite a lot. If it turns out to be short throated then play games with the magazine etc. if you are inclined.
 
Yama said:
Excuse my ignorance, but are the bolt faces of a 30-06 family cartridge and a 7x57 the same?
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Yes,.....the 8x57 which came first, was designed by the Germans...so it's meteric.....12 millimeters....or .473 inches...the 30-06 was patterned after the 8x57 and/or 7x57.....if the Americans had designed the 30-06 from scratch one wonders if it would have been an even half inch?...

and I think I may have found the answer to Claven2's "problem"...after much research and some searching I came across this.....I think it'll work...
280reamers006.jpg
 
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LOL. I wanted a 7x57, not a .280AI or .380 Rem!!! ;)

I'm of the school of thought that all the best cartridges were developed before 1939 ;)
 
Winchester never intended a LH short action 7X57. I promise.

If it bothers you that much call WGP and see if they have a LH bolt stop for a WSM, a SA follower, SA spring and block the mag box.

I'd leave it be.
 
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