Model 70 300WM TO 35 Whelen conversion. What would it require?

Leaf Litter

Lil-Rokslider
Joined
Sep 8, 2022
What am I looking at beyond a new barrel and bolt head to convert a Model 70 Winchester chambered in 300WM to 35 Whelen?
 
You would be better off to sell the .300 WM and buy a 35 Whelen.

I am not nearly as savvy on the Model 70 as I am on the 700 platform, but I would venture to guess that the feed lips on the action are opened up for the belted mag cartridge. What that means is that your finished project won't feed from the mag and you would end up with a single shot rifle. If you were going the other way, it would be a "simple" open up the bolt face and feed lips, change out the magazine follower, rebarrel and you would be good to go. Going the way you want is much, much harder.
 
Kind of what I thought. It's a top-feed internal mag but your point remains valid. Long action rifles are getting hard to come by and the price was great on this one, I passed on buying it for fear of an unnecessarily difficult project
 
You can always load down the 358 Norma to 35 Whelen ballistics.
I worry that cases with a bunch of empty space will have wonky SD and extreme spreads, but I'm not an experienced reloader so that's just my outsider logic
 
I worry that cases with a bunch of empty space will have wonky SD and extreme spreads, but I'm not an experienced reloader so that's just my outsider logic
You just load with a slow bulky powder that gets to 80% case fill.

Or consider a .350 Rem Mag. That would be a simple rebarrel. Maybe you would need a small spacer at the back of the magazine, but that usually isn't strictly necessary.

Jeremy
 
I worry that cases with a bunch of empty space will have wonky SD and extreme spreads, but I'm not an experienced reloader so that's just my outsider logic
4350 class powders and a 200 gr bullet would give you close to 100 case fill, and about 2800 fps.
 
The 35 Whelen is the 30/06 necked up to 35 cal. so I would start with a rifle that is a 30/06, 270, or 280. Then the bolt and magazine would work. You can't change the "bolt head" on a m70, so you would need a complete bolt from a 30/06, 270, or 280.
Another option is to get a 30/06 or 270 and have it rebored to 35 Whelen. JES does it for $300
 
The biggest thing keeping me from the 358 Norma is that I want this for a deer rifle and I feel like that's more gun than I need and definitely more gun than I want to shoot.

Axlrod- this info about the bolt head was exactly what I was looking for, thanks for chiming in. I'll keep looking for a 30-06 parent case rifle.
 
The biggest thing keeping me from the 358 Norma is that I want this for a deer rifle and I feel like that's more gun than I need and definitely more gun than I want to shoot.

Axlrod- this info about the bolt head was exactly what I was looking for, thanks for chiming in. I'll keep looking for a 30-06 parent case rifle.
I built a 358 Norma for Iowa deer hunting. I put a couple YouTube videos together on the cartridge and my rifle build if you’re interested:

Rifle overview:
Cartridge overview:
 
Iowa native here and I bought a stainless CVA scout in .35 Whelen for deer hunting last year. 25” fluted barrel and muzzle brake consistently shoot 1-1.5” off my trigger stick at 100 yards with Barnes 180s and 180 hot-cor handloads. 2” high at 100 and you’re dead-on at 200 and only 8.5” low at 300.

This rifle is very comfortable to shoot and accurate. Just make sure you have ear protection.

As an head’s up, ammo for .35 Whelen can be tough to find and it’s expensive.
 

Attachments

  • 0D15E24E-E1CD-4144-8654-87842AF36F06.png
    0D15E24E-E1CD-4144-8654-87842AF36F06.png
    169.5 KB · Views: 6
Last edited:
The 35 Whelen is the 30/06 necked up to 35 cal. so I would start with a rifle that is a 30/06, 270, or 280. Then the bolt and magazine would work. You can't change the "bolt head" on a m70, so you would need a complete bolt from a 30/06, 270, or 280.
Another option is to get a 30/06 or 270 and have it rebored to 35 Whelen. JES does it for $300
This is your best answer. Get a 2506/270/280/3006 M70 and put a new barrel on it. Or rebore.
 
I ended up just spending the money and buying a Tikka T3X light in 270 and ordered a 35 whelen AI barrel. Once I get everything put together it should be the improvement I was looking for over my 350 legend. I think a 200 grain Hammer bullet at 2900fps should be more than I'd ever need
 
Not sure you will hit 2900, maybe as it’s an ai, but 2700-2800 should be easy. Going to the range this weekend to test some 200g hammer loads in a whelen. The 203 shock hammer worked fine at 2400, add another 400 fps and it should really do the job.
 
Back
Top