weatherby box length ? (Mark v)

[myrifleisLapua]

Im going to use a mark v 30-378 action for my big bore build.
.550 magnum. The 378 case blown out to .55" 700gr at 2400 fps .
With the 800gr it has a c.o.a.l of 3.802" from the reloading data.
Between 3.760-3.790 with 700gr jacket or solid cant remember. Should be shorter with the cast bullets i plan on using. With the internal mag allow feeding of 3.802"? . Ive read the 378 had a box of 3.815" but the other cartridges had a shorter box. Pacnor wanted to know. They'll do the barrel and action work. Not bolt face mods needed thats a plus. But said they didnt know if it would feed.

 

[Broz]

Most all the 378 based Mark V's I have worked with had a box length just over 3.800" probably average is about 3.820"

Jeff

 

[myrifleisLapua]

The longest load is 3.835" with the hawk 800gr rn.

All other loads are 3.715"-3.790" with 600-700gr.
I think case is 3" ?

 

[jrsolocam]

Do not take this as gospel but I've read that you can get 3.85" with a kit you buy straight from Weatherby. If you look I believe there is a thread here on LRH.

 

[myrifleisLapua]

I think you mean the drop box kit. Guess its more than a piece of bottom metal if it allows but a slight longer cartridge