Burned throat

[WildRose]

Thanks to all for the information.
What about the 7mm on a 300Win Mag case, will that fit in my mag well which is 3.368? But that would require new brass, dies and a new barrel oh well just a thought!
Mudrunner, why do you say the 7 Rem mag and the WBY mag are, "nearly identical ballistically" ?
AIRBORNE

Talk to a good gunsmith you'd like to use about the 7mm STW. I think your existing barrel could be used.

 

[MudRunner2005]

Talk to a good gunsmith you'd like to use about the 7mm STW. I think your existing barrel could be used.

He will be limited by his magazine length in a MK-V that came factory in .257/270/7mm Wby chambering. Unless that mag box bar can be removed, and he can put in a .300 Wby follower. He might could just buy a .300 Wby mag box and follower somewhere. Then I agree 100%, go 7mm STW.

 

[WildRose]

Canhunter35 probably just revealed one of the biggest secrets in reloading! Long bearing surfaces on heavy for caliber bullets will line up better in the freebore, leading into the rifling, when compared to a shorter bearing surface in the same gun, period!

Think about it this way, if the freebore has a diameter that is usually .0005" over the diameter of the bullet the bullet is at maximum yaw when the front of the bullet is touching the bottom of the barrel and the rear of the bullet is touching the top of the barrel. The bullet can not yaw any more than this. If that bearing surface is elongated, for example a 195gr. 7mm EOL, vs. a 162 gr. VLD (Both Bergers), then the maximum amount the bullet can yaw is far less. When you solve for degrees off axis of the bore.

I believe this is why the SMK has such a reputation for accuracy. It has NOTHING to do with the radius of the ogive. The SMK has a comparatively, very long, bearing surface which aligns the bullets in the FREEBORE, almost immediately.

Long story short, I would look hard at a new barrel (sounds like your's is probably shot, or just have it set back if you can), keep it 7Wby. since you have all the equipment and make it a 1:8 twist, then shoot the 195's or if you really don't like bullets that big run a 160 Accubond or something similar. You really won't give up much in trajectory with the increase in velocity until you are probably past 500 yards. And let's be honest, shots past that distance are definitely the exception for 90% of us, even in this forum.

Just my thoughts, good discussion!

The way the ride up to the lands is tapered with the WBY's it's not a big deal either way.

Those chambers were originally cut with the intent of running light for caliber bullets at extreme velocities that were set way off the lands.

Unless you're shooting VLD's it really makes little difference with the WBY's.

 

[snox801]

Bob hart is a gunsmith in PA who was also a very accomplished shooter. He seems to do a decent amount of Weatherby.
If it was me before I would do anything I would try the hammer bullets first. They seem to be so forgiving. You should be able to push it very fast. If it also does not shoot well I would say you will then need a new barrel.

 

[redneckclimbing]

WildRose, just looking at the SAAMI specs for the Wby. chambers, which part are you talking about the leade or the throat itself?

I noticed that the Wby. specs actually call for a tighter throat then almost all other cartridges (usually .0004" over bullet diameter vs. at least .0005" over).

I personally have only worked up loads for two .300 Wbys. so I can't say I have any real experience with them. However, with the even tighter neck, a VLD with a long bearing surface like the 195 or a tangent ogived bullet with a long bearing surface like the 160 AB should, in theory, shoot even better compared to other cartridges, if you seat that bullet out longer giving it a chance to center in the leade.

How have yours done with long VLD's seated with say only one caliber of bearing surface in the neck? Just curious, thanks.