Wby Accumark Berger 300Gn Seating Issues

[kc0pph]

I have this Wby Accumark and when seating the bullets i have been running into some issues. I always set my bullets slightly shorter than the measurement i get via sticking a bullet in a fired case and closing the bolt. I then usually go about 15 thousands of an inch shorter than that.

When i do this with the Wby the VLD barley seats past the boat tail. I believe this is because of the freebore but not sure.

I hear a lot of individuals talk about seating .002" off the lands. How do i measure that in a 338-378?

Berger Reccomends seating bullets .040 to .130" from the lands.

I have never gotten into this part of reloading and cant imagine how to do this. I see a Horniday Tool but there is no 338-378 wby attachment for it (That i can see)...

Anyone have any tips for how to accurately seat these bullets?

[Broz]

The way Wby calibers get the extra velocity is the long freebore allowing a larger charge with out the pressure. You will not get to the lands with the factory 338-378 chambering.

Try seating some about .020" shorter that your mag box length. Just short enough that they wil feed through the box and not bind even when angled.

Then go buy the proper tool to measure o-give to case head in your non wby calibers.

Jeff

[kc0pph]

Well if i do that with the VLD's the tip of the case mouth would be on the ogive.

[Broz]

Originally Posted by kc0pph

Well if i do that with the VLD's the tip of the case mouth would be on the ogive.

The 378 case is 2.900 trim length right? ( I am going off memory here)

The mag box should pass a OAL of 3.800"

That is the best you can do unless you wish to single feed them.

Jeff

[Broz]

The freebore in your rifle is .361" if that helps you any.

Jeff

[kc0pph]

I am not at my reloading bench (its 10 miles away at the parentals house), and i dont have a case handy.

I tried to seat to 3.750" (What berger sent me using quickload), and they were "Crimped" on the ogive. Not good.

[sp6x6]

You dont want to crimp, that has to do with die set up. I dont have a 338-378, but loaded a 340 for over 20+. You could single feed as Broz, suggest, I have a friend that carries a few "first shots''. But with seating you should find something to work. A comparator of some type will help you with adjustments. You can do the old fashion, cut channel in top of brass, slot w/small jewlwers or small hacksaw, press in slight to hold bullet. Run into chamber and pull out carefull, that will give length to lands, I use a Sinclair tool for this, but with you free bore most of this is a mute point because you want to fit mag. I load for several Weatherbys, and you just find what they like.