Winchester model 70 magnum action

wwiiman

I have a later Winchester model 70 in 300 win mag
my question is can I use that magnum action to build a 300 H&H

Ray B

The action is the same size externally, but since the Win Mag is a shorter cartridge the magazine, follower and possibly the feedramp may need modification.

charliemeyer007

They were factory made in 300 H&H.

tsr1965

wwiiman,

I am not so sure that the 300 H&H will work properly in that action. The length is OK, and I have heard of folks building 300 Remington Ultra Magnum's on them. However, the follower, and possibly the magazine box would definately have to be changed, but that all might be for nothing, if the feel rails are too wide already. Yes, the geometry of the rails above the magazine, play a part in feeding. You can open them up for a larger diameter cartridge, but you can't close them up for a smaller one. The majority of the body of the H&H, is smaller than the Win.



Best

EDIT 1

quote:They made even the post-'64 (w/o changing the receiver length)in .375 H&H, same length cartridge as the .300 H&H, so changing from the .300 Win. Mag. should not require any ACTION alterations, just longer magazine box & new barrel; my .300 H&H pre-'64 magazine follower is not longer than a .30-06, just wider at the back, so any belted mag follower should work.

Basing things on what they have made from one action, does not mean that everything can be made from the action after it has been made into a complete rifle.

Most likely the bolt rails on the rifle have been cut, to a specific chambering...if that chambering has a wider body than the desired chambering, metal cannot be added back to it.

One more thing...it is the same length action they use on the 30-06 based length rounds...there are some other machining options that have to happen for longer rounds. Did you realize that they use that same 30-06 length action, to build the 300 RUM rifles...which is based on a 404 Jeffery?

Best

XXCross

Don't forget also that there needs to be a notch cut into the back side of the front ring on the action. (semi circular cut about 1/4 inch wide and 1/8 inch deep) This allows for the extra length of the 300H&H or the 375H&H.

MG1890

quote:Originally posted by wwiiman
I have a later Winchester model 70 in 300 win mag
my question is can I use that magnum action to build a 300 H&H


How late? Pre 64, push feed, post 64 CRF, what is it exactly?

richarda

They made even the post-'64 (w/o changing the receiver length)in .375 H&H, same length cartridge as the .300 H&H, so changing from the .300 Win. Mag. should not require any ACTION alterations, just longer magazine box & new barrel; my .300 H&H pre-'64 magazine follower is not longer than a .30-06, just wider at the back, so any belted mag follower should work.

Hawk Carse

Since Winchesters were regularly made in .30 Super (.300 H&H Magnum) and .375 H&H Magnum, I wonder why in the world they bothered with the short magnums of the 1960s. Hoping to sell ammo for other brand rifles?

wwiiman

My model 70 300 Win Mag is one of the later ones that came from Walmart as a gun and scope combo
I tried to put the 300 H&H in the magazine and there is not enough room for it to fit between the feed ramp and the back of the magazine well
even if I modified the feed ramp the opening on the top for loading between where the front and back scope mounts would be is not long enough to load the rounds straignt down

Ray B

I'm not sure if you have the M70 with the enclosed head or the non-rotating extractor, but: the ones that I've had experience with are a pre-war M70 300 H7H that I had rebarreled to 375H&H. No adjustments were made, however the openings in the action and the magazine were larger than the standard length model. the other was a M70 SuperGrade that was a post 64, when Win started reintroducing the non-rotating extractor about 1990. It was chambered for 338 Mag. I had it rebarreled to 375 RUM. the existing bottom metal would not work for the RUM and the gunsmith got new bottom metal from Winchester, which allowed the action to operate perfectly with the larger diameter/longer cartridges. I'm not aware of any milling of the receiver. If you have one of the enclosed head bolts - I don't have any experience with those.

25-06

Sir, you do not need to change anything but the magazine box by removing the spacer at the back by drilling out the spot welds and smoothing that area. Shorten the bolt stop and you are good to go besides the rebarrel. This was all we did to 7mm Remington Mags after rechambering to 7STW's. All the Winchester long actions are the same length, even the ones chambered for 30-06 type cartridges.