OAL and Weatherby Mags

[wpriest75]

I'm having some problems trying to measure OAL in 300 Weatherby Mag. No problem using the Hornady tool for a Weatherby in 30/06. Any ideas as to what is going wrong?

Thanks

 

[A382DWDZQ]

What kind of problem? Is it a Weatherby rifle? I've heard they are long throated, so that was the first things that popped into my head.

 

[wpriest75]

That’s what I thought but is the throating just for Weatherby cartridges? I have a Wby Vanguard in 30/06 and don’t have the problem. I’m wondering if I’m not fully chambering the Wby case. It’s a Hornady modified case but I’m using the curved version. The 30/06 case would be ‘short’ enough to chamber completely as the curve of the unit hits the receiver ring.
BTW I’ll message you re: your brass once I have enough posts and time

 

[TaperPin]

The weatherby’s throat is a lot longer - a 30-06 is roughly half the freebore of a 300 wby. It’s kind of crazy.

The industry standards for chamber dimensions are here:

https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

 

[wind gypsy]

You have not clearly stated what your issue is. Is the curved OAL tool hitting the receiver before the modified case is pressed firmly into the chamber? If so, the throat length has nothing to do with it. Only idea I'd have is unscrewing the modified case a hair if you're close to being there and using tape or something to keep it from moving before you can measure COAL or BTO.

There are ways to measure without using a hornady tool as well if you use the google machine.

 

[WeiserBucks]

SAAMI WBY cartridge throats are very long by design to reduce pressure, approach the lands with a heavy dose of caution.

All factory rifles, regardless of MFG, chambered for WBY cartridges will have that feature, WBY factory rifles that are chambered to a non WBY cartridge will have whatever SAAMI spec chamber is appropriate for the cartridge.

 

[TaperPin]

I'm having some problems trying to measure OAL in 300 Weatherby Mag. No problem using the Hornady tool for a Weatherby in 30/06. Any ideas as to what is going wrong?

Thanks

Are you trying to use a 30-06 case in the 300 wby chamber? No.

 

[wpriest75]

I have 2 Weatherbys --I measured OAL / Seating depth in the 30/06 without a problem as I have done for other calibers (308 Win 6.5CM). I bought the Weatherby 300 Wby Mag a week ago and figured while I had the bullets and the curved OAL tool out I'd see what kind of values I would get. I was trying boat tail bullets of different weights and manufacturers --what would happen is upon pulling out the gauge is the seating depth is such that it doesn't even cover the boat tail section-the seating depth is too little. After the first reply to my posting I started to think maybe the case was not completely chambered.
I was also wondering if only Weatherby proprietary cartridges have to the long leade.

 

[wpriest75]

SAAMI WBY cartridge throats are very long by design to reduce pressure, approach the lands with a heavy dose of caution.

All factory rifles, regardless of MFG, chambered for WBY cartridges will have that feature, WBY factory rifles that are chambered to a non WBY cartridge will have whatever SAAMI spec chamber is appropriate for the cartridge.

Thanks for the info and link

 

[wind gypsy]

SAAMI WBY cartridge throats are very long by design to reduce pressure, approach the lands with a heavy dose of caution.

All factory rifles, regardless of MFG, chambered for WBY cartridges will have that feature, WBY factory rifles that are chambered to a non WBY cartridge will have whatever SAAMI spec chamber is appropriate for the cartridge.

Curious - why is approaching the lands in a weatherby different than any other cartridge? Why would say 40 thou off the lands be dangerous but 200 thou safe?

 

[WeiserBucks]

Curious - why is approaching the lands in a weatherby different than any other cartridge? Why would say 40 thou off the lands be dangerous but 200 thou safe?

In a nutshell, more throat=less pressure. WBY has been all about speed for decades and a long throat is one way to get big speed without big pressure and still qualify for SAAMI standardization.

 

[wind gypsy]

In a nutshell, more throat=less pressure. WBY has been all about speed for decades and a long throat is one way to get big speed without big pressure and still qualify for SAAMI standardization.

Of course but what does that have to do with a weatherby being more risky to approach the lands with seating depth than any other cartridge?

 

[WeiserBucks]

Of course but what does that have to do with a weatherby being more risky to approach the lands with seating depth than any other cartridge?

Because other cartridges weren't designed by the MFG to have a mile of throat to be at a safe pressure. The vast majority of cartridges are designed by the MFG and certified by SAAMI to be safe with a much shorter throat than WBY.

 

[Wapiti1]

Because other cartridges weren't designed by the MFG to have a mile of throat to be at a safe pressure. The vast majority of cartridges are designed by the MFG and certified by SAAMI to be safe with a much shorter throat than WBY.

But loading long to try to get closer to the lands lowers pressure since the starting internal volume is higher. The caveat to this is if you are jammed into the lands, then you may see a spike.

Realistically, in the .300 Bee, many bullets won't be in the case when touching the lands or they'll barely be hanging on. The spec throat length is .361".

Jeremy

 

[FLHunter87]

All weatherby magnums are like that. I have a 257 weatherby. You can play around with seating depths, but the weatherby like a little jump. The Freebore part is normal. You'll find something that shoots. Plenty of people have a 300 weatherby mag and can shoot 5-700 yards easily and relatively good groups.