Home Forums Hunting & Shooting Custom Rifles & Wildcats Tell me about the 257 Weatherby...

I once did a calculation for a similar situation and it turns out the energy carried by the projectile due to its angular velocity is pretty small compared to that from the linear component.

Changing the twist from 10" to 12" won't save enough energy from rotation to put into forward motion to get the reported velocities.

I've seen references to pressure tested data that twist rate effects pressure very little to not at all. Moderate twists don't enable screaming speeds conventional wisdom be damned. .

You don't need a Magnum action for a 257 Weatherby (length wise) as it is about the same length as a 270 WCF. So if you have a REAL magnum action (3.6" oal loaded) I would not waste it on a 257 WM.
Better to sell it for big bucks and buy a MOA Vanguard.

Will it do anything a 270 WCF will not? I doubt it in practical hunting. It's a favorite Antelope cartridge where I live, but I manage to kill a couple every year and don't own a 257 WM.

Still a neat cartridge and I am no one to talk as I built a 244 H&H.

Thanks for the advice and you're right. It is not a true magnum action - just a standard LA with a magnum bolt face. If it was then a 300H&H would be in order.

I already own a 270 so I don't really need a 257WyM but need has nothing to do with it!

RH

I think you're good-to-go. Just pick a maker and order yourself a nice 25 caliber barrel! Ought to be a fun build.

I really HATE every one of you

Other than lusting after a .280 AI for some time now and knowing that, it'll be my first real custom. I now somehow seem to think I need a .257. And of course I found a NIB SPS just down the street from where I work.


**Must resist**

Throw a 100gr X at 3600fps and head to the barn.

More temptation...

Thinking on how twist rate affects pressure and the possibility of attaining more/less velocity, I built three rifles to do some testing over a three year period, a 22/250 AI with a 1-15 twist, a 223 with a 1-9 twist, and a 22 PPC with a 1-9 twist.

I wanted to see just how fast I could push a Berger 22 caliber 65g HP with extreme accuracy, and how the 1-9 twists would enable the bullets to blow up better on p. dogs.

On the 22/250 AI with the 1-15 twist, I worked up a load in the 27" Hart Barrel with the 65's at 3700 fps that shot very tiny groups. This bullet was so effective on those large coyotes it was hard to believe. Too bad berger quit making this bullet. This load would blow bobcats and foxes half in two. I got this info from a fellow hunter that had a rifle built in the same way, he painted air planes for a living and I thought sure as heck that he had sniffed too much paint. He was spot on in his loads.

Concerning the 223 and the 22 PPC with the 9" twists,I built the 223 on trued 700 action, McMillen Hunter class benchrest stock with a 27" Hart barrel MHV Barrel. On the 22PPC I had 24" Hart #7 contour barrel Put on a Sako A-1 Action in a McMillen Sako Varmint stock.

I had several other custom 223's of the same design but with a 1-14 twist, and at least 3 other 22 PPC's in Benchrest rifles with 1-14 twist rates, all these rifle's barrels were cut with the same reamer that had .0005 over bullet dia throats and zero freebore, with 1 1/2* leade angles.

During the testing of the 223 with the 1-9 twist, I noticed that the sweet spot in accuracy that was easily attainable at the higher node in the 1-14 twist was not attainable in the 1-9 twist without super hard extraction and opening up the primer pockets in the IMI brass that is super tough. Also, the range of powder weight in the 1-9 twist that would shoot tiny groups was very small, indicating that as temp and barometric pressure changes that so would the load's accuracy potential.

With all the 22 PPC's that I had, the 1-9" twist was very picky on what it liked to shoot bug holes with. A 22PPC with a 1-14 twist is one of the most "user friendly" cartridges a guy can play with. No doubt that the 1-9 twist was no where near as user friendly as the 1-14 twists, due to pressure spikes.

This is way off topic of a 257 Weatherby, but thought that it may be interesting at how twist rates affect pressures to some of you.

Damn blue tape......

That's the rifle I lust for in a .280 AI, wouldn't have a problem in the world with a matching one in .257 either.

Only wish I had another zero at the end of my checkbooks balance.

Love my 257 Vanguard. Test target has a 1/2" group. First 10 boxes of ammo cost more than the rifle. Still, no regrets.

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cripes, and here i was thinkin i couldnt possibly justify another deer rifle, and then you folks go posting up some pix of these 257's. and i have a .25 fetish already. i see a new project and a thiner wallet in the future.

some questions...

1) how much oomph does the .257Wby gain over the 25/06AI ??
i ask because i have a remmy sendero stainless fluted in 25/06, might make more sense to punch it out. it has a 26" tube..but i'm leaning towards something lighter. and that gives me an excuse for another gun.

2) i'm a cheap bastid at heart, and already have a bunch of 7mm rem mag brass (and no 7mag either)...aside from possibly neck turning, will those do for reforming to .257wby? or i should say, can i reform those with standard full length .257wby dies so i dont have to buy a set of forming dies?

3) .257Wby versus .257STW...what made you go with the .257Wby?

4) buulets on whitetails...how do the 117's/120's hold up at zippy speeds?

all thoughts & opinions welcomed.

Regards;

Gerald

Cheap and 257 Weatherby don't mix.

STWs just burn up barrels faster and are hardly a "factory cartridge"

All you need for deer in a 100 gr TSX it will NEVER come apart.

Interesting stuff Keith .

Have been playing with my first .257 Weatherby and am so far favorably impressed. Have killed a pronghorn, a pig, my biggest Whitetail buck and a whitetail doe. Additionally, a hunting partner killed his pronghorn with it too. The farthest anything has run was about 30 yards. Been shooting 80gr TTSXs at about 3700. Not a hot load by any stretch, but that's what it likes. Also shows great promise with 110gr Accubonds and 115gr Ballistic Tips. Haven't found the magic load yet with 100gr TTSXs. They don't shoot bad for me, about an inch or so, but not nearly as well as the stuff the rifle really likes. I have been using Winchester 7 mag brass, but I think as I attrit that, I'm gonna replace it with Norma Brass. Not completely satisfied with the runout I am getting from the Winchester brass, with most stuff coming in at about .003" to .004". IMR 7828 does pretty well, and R25 may end up being better, especially with heavier bullets. Not done with load testing yet, but so far, with both 110gr Accubonds and 115gr Ballistic Tips and R25, the warmer the charge, the tighter the groups. Also eager to see what I can do with 115gr VLDs, as the 155gr version has been the fastest killer I have used in my .308.

John

.257 Wby is a wicked mother.

I dont know how you blokes think you can get good performance from a mere push feed. Don't you listen to the CRF experts? A rifle is not worth zip for anything unless it is a CRF.

IknowIknowIknow.............lol...........mine gets good performance "sniff sniff."