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.257 Weatherby Magnum

rcoody

Well-Known Member
Joined
Jul 1, 2015
Messages
1,026
anybody out there shooting one. We have all these new 6.5 mm cartridges. I am kind of old school. Why should a 6.5 Saum be so much better than Weatherby's original.
 
One really good thing is the SAUM cartridge doesn't have that belt. Belted cases are a problem for getting best accuracy.

Another's the sharper shoulder angle which lets primers detonate more uniformly; shoulder setback from firing pin impact is less. And that leads to longer case life.

And its short, fat case lets powder burn more consistently. All the really accurate cartridges are short and fat for their caliber.
 
I've never had any problem getting accuracy out of any of my belted cartridges...Once you fire-form them to the chamber and neck-size, they headspace off the shoulder (like a non-belted) and the belt, so there should be no room for issues as far as the belt itself is concerned. Some of mine shoot sub-1/2 MOA (yes, all the time, as long as I do my part). So let's not get into a debate about the frequency in which these rifles shoot how small (or large) of groups.

I will agree that the sharper shoulder angles (35-40 degrees) have nothing but positive advantages, like the Ackley Improved calibers. I prefer the 40-degree versions of the AI calibers, myself.

As much as I hate to admit it, the short & fat powder columns do seem to continue to prove to be just as efficient (in some rare instances more efficient) as their full-size magnum counterparts with all the advancements in powder technology these days.
 
r, my .257's are my most accurate of all. The 26" barrel and hand loads of 115 Bergers shoot well for me on deer and javelina. Guess I'm old school also and quite resistant to change. Good luck
 
I have a 257 wby in a factory MKV. The only thing done to it was a custom stock and bedding job. It shoots a legit 1/2 +/- moa. I also have a 6.5x284 Norma custom that shoots bugholes. It's not necessarily one of the new hot rod 6.5's but it's a 6.5 none the less.

I've used both rifles on deer sized game out to 500+ yards. Now with that said I realize that's a chip shot for many of the more skilled people on this forum and I respect that. I'm just not comfortable with my capabilities shooting game further than that yet. However, none of the animals I have taken argued either way about a super mag or old school. With the weatherby I would still be a little less apt to try a much further shot only because of the lighter weight bullet offerings. Perhaps when I put a longer barrel on, with a custom chamber, I will be more confident with a bullet heavier than the 100gr TTSX or 110gr acubonds I've been using. With the Norma, it's a no brainer using the 140 grain bergers. That particular bullet has proven itself to a distance a lot further than 500 yards with many other hunters and target shooters.

Last year I was in Montana shooting steel with a very knowledgeable man who competes in sniper matches at a national level. He shoots a 6.5 SAUM. He loves the caliber and told me that because of the velocity that round cranks out, he has a minimal amount of adjustments he has to make when shooting a timed course. But my Norma, shooting over 200 fps less, with the same 140 Berger, made it to the same steel targets. Only difference, of course, was the drops and windage. Long story short, I'm not arguing either way. I think what works for you and your hunting needs is all that matters. Pick what ya like and enjoy yourself.

Best of luck,
Erik
 
One really good thing is the SAUM cartridge doesn't have that belt. Belted cases are a problem for getting best accuracy.

Another's the sharper shoulder angle which lets primers detonate more uniformly; shoulder setback from firing pin impact is less. And that leads to longer case life.

And its short, fat case lets powder burn more consistently. All the really accurate cartridges are short and fat for their caliber.

I can't see how getting accuracy would be a problem with a belted case. You just ignore the belt and resized it like any other cartridge. And let's see, maybe it was the 300 H&H Magnum that won Wimbeldon many years ago.

There may be some minimal advantage to short and fat. The current light varmint bench rest world record group was shot with a 6mm PPC. The current 1,000 yard ten shot bench rest world record group was shot with a 6mm Dasher. Remember though, that the world record group for light varmint had stood for 20 years and was shot with a 222 Remington which isn't short and fat. If everyone decides to shoot short and fat cartridges it only stands to reason that eventually a record will be broken by one of them.

In my opinion, short and fat isn't that much of an advantage. Fat means you can't get as many cartridges in the magazine. I know they're all the fad but I don't want any of them.
 
I can't see how getting accuracy would be a problem with a belted case. You just ignore the belt and resized it like any other cartridge. And let's see, maybe it was the 300 H&H Magnum that won Wimbledon many years ago.
Best accuracy the .300 H&H match rifles produced in the late 1930's when Ben Comfort did that in 1935 was about 15 inches at 1000 yards. They all used new cases to do it. His record was broken in almost every year later by military team members using new cases.

The problem is, belted cases are not full length resized like rimless ones. Rimless ones get their body sized down from the pressure ring forward. Belted ones typically have a ridge left on their first firing as the belt's back a couple thousandths from the chamber headspace stop when fired; it stays there and interferes with how the case slams forward from firing pin impact on the next firing. That causes irregular barrel whipping before the bullet leaves the barrel.

When the 300 H&H was finally replaced with a more accurate cartridge in the 1960's (Fred Huntington's .30-.338 and the .300 Win Mag) as a long range match cartridge, people winning and setting records with it got better accuracy with new cases than conventional full length sized ones. Neck only never produced consistent accuracy. So they cut the top and bottom of a full length sizing die off, then used it to resize a full length sized case squeezing down that ridge and sizing the case back to virtual new case diameters all the way back to the belt. Finally best accuracy (about 6 inches at 1000 yards) was possible and consistent for testing ammo. Larry Wilis' collet die for belted cases now does the same thing.

Prior to that time when the H&H round was popular, the best scores were shot with new cases. As did the military teams shooting Win 70 .300 H&H bull guns in long range matches. They tried full length sizing .30-.338 and .300 Win Mag cases in the '60's but gave up and used new ones. Civilians used that body die before or after full length sizing their fired belted cases Such improvements were the reason why the target scoring rings were reduced in the early 1970's down from their original sizes set around 1900.

In my own tests with .30-.338's, neck only sizing produced 10 to 15 inch groups at 1000 yards. New cases or proper full length sized ones resized with a body die all the way to the belt shot under 6 inches. 15 to 20 shot tests for credibility.
 
Rimless cases aren't sized completely either. I also have never noticed the pressure ring on the multiple belted magnum I shoot; at least not any different than those rimless cases I use.

I will grant you, however, that resized cases and even neck sized cases don't always give as good accuracy as new cases but that's true of rimless as well as belted cases.

h29zo67.jpg


My 257 Weatherby load.
 
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