I have a Model 70 stainless classic in a 338 WM
(CRF). And I was wondering if I can replace the magazine box, magazine spring and the follower from a 375 H&H stainless classic, to obtain longer C.O.A.L in the 338 WM.

If possible where would be the best place to buy the parts?

Thanks in advance.

Steve

Did that for M-70 300 Win Mag twice. Once I took out the spacer and spot welded mag box, once replaced the box as first method was too much work. Don't forget to modify or replace the bolt stop. In both cases I did not replace the spring. If you have feeding issues (if you modify the box) look at the rear and make sure you have clearance.

I did this with a push-feed .338 many years ago. Ordered a .375 box, stop and s.s. follower from WW. Opened the throat so that I could seat 250 Noslers out to about 3.6 oal. Once you do all this check to see if it will eject a loaded round without hanging up. Now after many years of use mine wants to pop the last round from the magazine if the bolt is cycled slowly. I have thought about trying to fit one of Duane Wiebe's followers and mag boxes to see if I can clear this up.
C.G.B.