I was wanting to build a 375 H&H on my pre 64 action and are now finding a new possible problem. I was informened that the action from a pre 64 in 300 and 375 H&H was different, longer. The length of the inside of my box magazine is approximately 3.6, in the books i have the max length of the .375 H&H is 3.6. The remington box mag is approximately 3.7 long.

Can a Pre 64 300 or 375 H&H owner please measure the inside length of their box magazine for me, or if anyone knows this information and can share. I dont know what kind of clearence i need in a box mag when using a 375 but remington sure does not have much.

thanks in advance

I just measured mine and it's 3.6 It started out life as a 300 H&H and was rebarreled to 375 H&H

I can't imagine them using a different mag box from one to the other. That would be like using a different mag box for a 270 and 30-06

Matt Norman:

I agree with you, Remington only makes one, i was told by a smith there was a difference in mag length.

I guess you dont have much free play between the tip of the bullet and the end of the mag. I did not know if that little of play would effect the nose of the bullet during recoil or help it. And i am guessing factory ammo will fit in the mag just fine.

thanks for the reply

All factory ammo that I have used (Federal, Winchester, and PMP) has fit fine. No, there is not much room. Bulltet tips will become battered after awhile, but then they are more of a rounded off tip to begin with.

It depends on what yours started out as. If it was a 300/375 originally, it had the right mag box. The mag box for that was longer than the std 30-06 or 300/338/264 mag boxes. The actions are also different in appearance but not overall length. The difference is in the loading port cutout and is readily identified when compared to a standard action.

If its an 06 or the like all you have to do is knock the block out or reweld it, cut the rear action ring back a bit, do a little rail work. and re barrel...None of this is a problem..Dennis Olson can do it for you and not break the bank...Dennis Olson, Plains, Mt. tel. # 406-826-3790...