Load data for .257 Weatherby Mag?

[driftrider]

Hello all,

I've got a .257 Wby Mag on it's way to me, and I'm looking for some load information.

I will be using necked down .270 Wby brass. I wanted to try some 7mm Rem Mag or 264 Win Mag necked down, but everybody is fresh out. I couldn't find any actual 257 Wby brass either.

Preferred bullets are the 100 grain Barnes TSX BT(or Tipped TSX), 110gr Accubond or 115gr TSX FB. I have a pound IMR 7828 on hand, and I am looking to pick up some WC 860 milsurp powder that I think should work well and cost a lot less, but I can't really find any load data for it with the .257 Wby Mag. So if anyone has any recipes they'd like to share, I'd appreciate it.

Thanks,

Mike

 

[rcmodel]

Every reloading manual I own has lots of .257 Weatherby data in it.

Get sum!

As for using homemade brass & unknown surplus powder for load development?

How much reloading experience do you have?

rc

 

[driftrider]

I've been handloading for 6 years. I've handloaded for .223 Rem, .22-250, .243 Win, .30-06, 300WSM, 7mm STW, 9mm Parabellum, 45ACP, 45 Colt, .454 Casull, and .44 Mag. I've been around the block a time or two, thank you.

I do have some load data for the .257 Wby, but I don't have data for the bullets or powder I want to use. That's why I'm asking here. I wan't to use milsurp powder because, in case you haven't noticed, brand name powder has gotten a bit on the expensive side of late, and it can be hard to find. WC 860 can be had for $45/8lb jug, compared to $20-25/lb for name brand stuff. WC 860 should give good performance in the 257 Wby, and, as an added benefit, being a military ball powder it should burn with a lower flame temp which should lengthen barrel life, all else being equal.

As for forming cases, necking down a case is a simple operation, as long as the cases are properly lubed. 270 Wby to 257 Wby is child's play, and 7mm Mag to 257 Wby isn't too tough either. The cases come out a bit short in the neck, but usable.

But thanks for your help, anyway.

Mike

 

[jgh4445]

Hey drift....I had the exact same thoughts as rc when I first read your post. If you re-read, you'll see how we could imagine you to be a newbie to reloading. The part about not being able to find 257 info was a red flag to me too. RC has been around the block a time or two also and was just trying to head off a possible bad situation given the lack of info he was given about your experience level. You'll find the folks here more than helpful and also more than careful and caring as a rule.

 

[driftrider]

My problem is that I can't find specific data for the bullet powder combinations I want to use. I've found data for IMR 7828 for the 257 Wby, but not with Barnes TSX or Nosler Accubond bullets. I have some 7828 on hand that I'd like to try, but I, too, am cautious about handloading without at least some guideline to go by. I know that there is one person here (GooseGestapo I think), that loads for the 257 Wby AND uses the WC 860 powder, but while I've searched the forum and found his posts mentioning that he uses 860, I can't find where he's mentioned his recipe.

The point is that I know enough about handloading to not lose any body parts. I'm very cautious about my approach to this hobby. I also know enough to know that I don't know everything and that there are others who's experience might be helpful. That's why I'm here. I could just load up some rounds with the 7828 I have with data from similar weight bullets, but because the design of the TSX is different that a conventional lead core bullet, pressure levels are also different. Better not to wing it, IMO.

Mike

 

[Grumulkin]

As far as load data is concerned, I presume you are going to start in the lower end of the load range. If that is the case, you can use any data for a particular powder with a given bullet weight provided bullet construction is similar (i.e., jacketed or monometal). In a case the size of the 257 Weatherby, you won't find any pressure difference when using magnum vs regular primers. I don't think using necked down 270 Weatherby cases will be a problem.

IMR 7828 should be a good powder to try though my load of choice is with RL-25. I've never used military surplus powder; I probably ought to try it sometime.

 

[mistasprung]

My reloading results with my 257 wby Rem. 700 SPS

Here'a nice group that I'm proud of. It measures .283 inches.