M70 build, would this work?

[MTHunt]

Well I am trying to figure out what to do for a long range rifle I keep flip flopping back and forth on what I want to do.. Money is tighter than I thought it would be so I got an idea.
I have a M70 Classic in 338 win mag that sits in the safe.. Used it on a few deer and elk but that's been it.

I was looking at the Pac-nor site and thought, hey I have an action that unfortunately has a mag bolt face so I have to stay in that arena. But if I have them chamber and barrel my M70 in 28 Nosler I can go with a tighter twist to help stabilize the bigger bergers.. Would this work? Or would it be a good idea? A lot cheaper than buying a new rifle and can customize the barrel the way I would like it.. And use an action that otherwise just sits.

 

[MudRunner2005]

.28 Nosler is based on the RUM calibers, which uses the same magnum bolt face, but because the cases are fatter, might require some extra work to the action to make it cycle properly.

You could always just go with a 7mm STW, and you wouldn't have to modify anything. Just blueprint the action and install the new barrel.

 

[Garycrow]

You've got to change a lot of stuff on a M70 .338 win mag to make a 7mm STW work. The factory .338 magazine will only take a 3.340" round. 7mm STW won't fit.

You need a new magazine, follower, new bolt stop (or shorten the old one) and new or shortened ejector. After all that to do it right you'd need to mill the ejection port bigger although many have converted them and not opened up the ejection port. It'll work but you don't have as much room as in a factory M70 7mm stw. The 28 nosler would actually probably be easier because it's shorter, but the wide case would likely mean you'd have to tweak the feeding anyway.

 

[FEENIX]

Well I am trying to figure out what to do for a long range rifle I keep flip flopping back and forth on what I want to do.. Money is tighter than I thought it would be so I got an idea.
I have a M70 Classic in 338 win mag that sits in the safe.. Used it on a few deer and elk but that's been it.

I was looking at the Pac-nor site and thought, hey I have an action that unfortunately has a mag bolt face so I have to stay in that arena. But if I have them chamber and barrel my M70 in 28 Nosler I can go with a tighter twist to help stabilize the bigger bergers.. Would this work? Or would it be a good idea? A lot cheaper than buying a new rifle and can customize the barrel the way I would like it.. And use an action that otherwise just sits.

The .338 Win Mag is no slouch, how does it shoots now?

 

[MudRunner2005]

You've got to change a lot of stuff on a M70 .338 win mag to make a 7mm STW work. The factory .338 magazine will only take a 3.340" round. 7mm STW won't fit.

You need a new magazine, follower, new bolt stop (or shorten the old one) and new or shortened ejector. After all that to do it right you'd need to mill the ejection port bigger although many have converted them and not opened up the ejection port. It'll work but you don't have as much room as in a factory M70 7mm stw. The 28 nosler would actually probably be easier because it's shorter, but the wide case would likely mean you'd have to tweak the feeding anyway.

I'm not an M70 guy, so I had no idea the mags were shorter. In that case, I'd go 7mm RemMag, if the max OAL is 3.340".

My bad, I figured they were similar to a 700, where all LA's were around the same 3.70" length. Learn something new everyday.

 

[AZShooter]

You didn't specify which model 70. I was able to take a push feed post 64 model 70 that was a 300 win mag westerner model and convert it to shoot the 300 RUM. Didn't have to touch the feed rails. Only needed minor work: a Wyatt's mag box. Also altered the bolt stop. Used same follower. My gunsmith may have worked on the feed ramp but honestly don't know. It holds two round in magazine and feeds fine.

link to Wyatts: Magazine Boxes, WYATT'S OUTDOOR, INC.



I would suggest that once those alterations are done the 28 Nosler would fit and feed as well. Give Wyatts a call they can make some suggestions.

Find a RUM case to see if it will pass the feed rails of your rifle. If it does it will make the switch much easier.

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An after thought...... what about trying some 300 gr Berger hybrids or even the 250s in your 338? It should have the correct twist and it wouldn't take much effort to give them a try.

 

[IdahoCTD]

You could also do a 7-300wm with very little effort. The mag boxes have a spacer at the rear on most magnum actions that can be removed for more length. Or just buy a Wyatt box and make it even longer.

 

[MTHunt]

The .338 Win Mag is no slouch, how does it shoots now?

.

If it shot well I pry would just keep it. It has shaken one scope to death with recoil. And the barrel gets so warm that it throws fliers after 2 shots.. 2 shot groups are good but that's it.

 

[MTHunt]

I guess maybe the 28 nosler wouldn't be the one to try.. I didn't realize the M70 mags where shorter. If the spec of a 338 win mag is 3.340 and so is the 7mm rem and the 28 nosler I thought they would work, forgot about the fatter case.

 

[MudRunner2005]

I guess maybe the 28 nosler wouldn't be the one to try.. I didn't realize the M70 mags where shorter. If the spec of a 338 win mag is 3.340 and so is the 7mm rem and the 28 nosler I thought they would work, forgot about the fatter case.

7mmRM and .338 WinMag use a nearly identical case, so it should require nothing more than a simple barrel swap.

 

[Capt RB]

7 lrm

 

[MTHunt]

7 lrm

I never thought of that one.. Have only read a bit about it.. Any experience?

 

[fisherman983]

A 264 win mag and possibly an extended mag box depending on how long yours is now.

 

[MTHunt]

You didn't specify which model 70. I was able to take a push feed post 64 model 70 that was a 300 win mag westerner model and convert it to shoot the 300 RUM. Didn't have to touch the feed rails. Only needed minor work: a Wyatt's mag box. Also altered the bolt stop. Used same follower. My gunsmith may have worked on the feed ramp but honestly don't know. It holds two round in magazine and feeds fine.

link to Wyatts: Magazine Boxes, WYATT'S OUTDOOR, INC.



I would suggest that once those alterations are done the 28 Nosler would fit and feed as well. Give Wyatts a call they can make some suggestions.

Find a RUM case to see if it will pass the feed rails of your rifle. If it does it will make the switch much easier.

-----------------------
An after thought...... what about trying some 300 gr Berger hybrids or even the 250s in your 338? It should have the correct twist and it wouldn't take much effort to give them a try.

Sorry yeah its m70 classic stainless from oh pry late 90's when I got it. Has the "new style controlled round feed" I am not really sure what its called. I can see why 700's are easier to build on. Lol