375 h&h to 300 winmag

[AKsavage907]

I want to gain more magazine length for my 300 win mag. Can I take a 375 h&h action and put my 300 win mag barrel on it to get a little extra mag length? if so how much do I gain? I have a 110 SF now what modifications would I have to do to the h&h the magazine to get it to feed correctly? I am also assuming the bolt spacing is the same on the 110 and the h&h this matters because I would want to put it on my stockade stock.

Thanks for all your help

[Blitzfike]

I converted a model 111 in 30-06 to 458 win mag and just adjusted the feed lips to make it function. It will hold a factory 500 grain solid within the mag box. This is an older 111, so things may be different with current models.
Also sent you a PM.. Jim

[AKsavage907]

Thanks Jim, that's what I figured about bending the lips since the h&h is the parent round for the 300. I was mostly wondering about the action length.Does anyone know if the h&h action is longer than the standard 110? or at least is there more room because of the h&h mag? If so what would be the max OAL you could put in a 375 h&h?

[bootsmcguire]

Don't know the max length, but yes on a LA-SF a H&H/RUM length mag can be fitted to standard LA-SF action. It will require the rear of the port in the bottom of the action to be machined back and a new tab slot cut in to handle the added length. It may be easier to just pick up a H&H/RUM rifle for a donor and put your barrel on it.

The action itself is not longer. Only the port in the bottom is cut out longer. Also IIRC the front baffle on the bolt is stepped to allow the bolt to travel just a bit further back to reach the rear of the longer magazine.

[AKsavage907]

Ok yeah that is exactly what I was thinking of doing. Is getting a donor H&H rifle and putting my 300 win barrel on it just to gain a bit on the mag length. bolt head is the same size right for the 300 win and H&H?

[bootsmcguire]

bolt head is the same size right for the 300 win and H&H?

yup