WBY MKV for large bolt face magnums?

[wato338]

Some experienced members may be able to help me ,

i have two of the old stainless MKV actions and would like to build them into .338Norma mags one is full length ready to go and the other was a 300win so i have milled the bolt stop slot forward and got rid of the spacer in the mag well insert and have the .378 extractors on order ,one will be a prone rifle the other my lighter carry around hunting rifle . i chose the Norma Mag as it fits in the magazine with the 300gn SMK seated right out to keep powder space .

here is my concern- has anyone had problems with the extra thrust on the bolt after opening/chambering for the lap mag bolt face?

Thanks

 

[MagnumManiac]

Some experienced members may be able to help me ,

i have two of the old stainless MKV actions and would like to build them into .338Norma mags one is full length ready to go and the other was a 300win so i have milled the bolt stop slot forward and got rid of the spacer in the mag well insert and have the .378 extractors on order ,one will be a prone rifle the other my lighter carry around hunting rifle . i chose the Norma Mag as it fits in the magazine with the 300gn SMK seated right out to keep powder space .

here is my concern- has anyone had problems with the extra thrust on the bolt after opening/chambering for the lap mag bolt face?

Thanks

The bolt face is the same as the 300/338-378, 378, 416 and 460, no need to worry about bolt thrust.
If you keep oils and lube off your brass, bolt thrust isn't a problem, even with the 50BMG.

Cheers.
gun)

 

[Deleted member 46119]

Quote from Weatherby: "Get a 378 Extractor and open the bolt face. You could get one from us but the custom shop gets a 378 Extractor and opens the bolt face. An extra $300 for a LM bolt but that's what we do"

I'm pretty sure the Mark V bolt can be opened all the way to 505 Gibbs size (CheyTac)