257 Weatherby Vanguard S2. Load development. New data

Eagleye said:
Try IMR 7977 or Retumbo. Both shoot great in my Vanguard II 257 Weatherby.
Like yours, it is in a Boyd's Laminate Classic. I have a pressure point under the
barrel, about 3" from the front of the stock.
I also had good results with IMR 5010, but it is obsolete. [I have 6 lbs, lol]
Am going to try Vihtavuori N570, since it is very slow burning also. Dave.
Click to expand...

I have used Retumbo and 110 accubonds with my 257 weatherby and got .5" accuracy and 3475 fps velocity with 71.5gr
 
pacobillie said:
This post has been updated since it was originally posted. I have abandoned the idea of a pressure point.

Here is my predicament. I am trying to develop a long range hunting load. The rifle is a Weatherby Vanguard S2. I upgraded the stock to a Boyd laminated stock, and the action is bedded. The barrel is free floated.

I have tried three powders thus far: IMR 7828 SSC, H1000, and RE-25.

I have tried two bullets: Hornady ELD-x 110 grains, and Hornady Interbond 110 grains.

At the beginning, I had decent grouping (once) with the ELD-x bullet, 68 grains of IMR 7828 and the rifle in the original synthetic stock. (I sold it. So, I cannot go back to determine if it was a fluke).


I have been unable to duplicate the same results with the new Boyds stock. Rather, my best group with the ELD-x has been with 66.5 grains of IMR 7828 SSC (about 0.7 MOA, but I am unable to duplicate the accuracy with the Interbond. The best load thus far with the Interbond is 70.4 grains of of H-1000. Stringing is vertical. Accuracy is about 1.3 MOA. Velocity is 3341 fps, out of a 24 in. barrel. No signs of pressure. Hotter loads are worse, accuracy wise.

I have not found an accuracy node yet with the RE-25 powder and the Interbond. I have gone up to 71 grains, for 3325 fps.

BTW, I am using 7mm Rem Mag Hornady brass, that has been annealed and resized to 257 Wby mag. Brass is slightly heavier (thicker) than Wby brass. Thus, loads are less than published max loads. The brass has been weight sorted.

Although it shoots well, I do not trust the ELD-X to perform well on game at those velocities (about 3300 fps).

Since I cannot get the Interbond to group, I am considering trying something different. Options include the 110 gr Accubond, the 100 gr Barnes TSX, or the 110 grain Nosler E-tip. Any thoughts or input?
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Barns 100 tsx and H1000 gave me excellent accuracy, just not enough speed.. settled on IMR 4831..
Happy medium
E tips wouldn't group in my rifle..
Have you tried to full lenght size or are you only neck sizing?
 
Have you considered Swift Scirocco in .25 cal?

They like a jump which could be beneficial to the long throated Vanguard.

They would be a slightly stronger option to the accubond.They can be finicky but they will show up to shoot when you get em tuned.

The powders you are using are fine.

H4350 is one I’ve relied on when chasing accuracy.

You could also try a flat based bullet.My 25/06 really likes flat based light bullets.Some just prefer flat base to boat tail.I’m just suggesting this to nail down what the rifle may like.
 
Big bore dinosaur said:
Barns 100 tsx and H1000 gave me excellent accuracy, just not enough speed.. settled on IMR 4831..
Happy medium
E tips wouldn't group in my rifle..
Have you tried to full lenght size or are you only neck sizing?
Click to expand...

Full length sizing, but with very little shoulder bump. The resized case is a fairly tight fit in the chamber. The latter appears to be on the slightly short side.
 
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For all the weatherbys that I have Reloaded, some are picky..
Welcome to the world of high pressure curve ..finicky 2 tune.
I like to keep the case tight to the chamber and set my full-length die on the tight side to reduce case head expansion. But on the other hand I got better accuracy by not camming the bolt with a piece of brass that is a whisker too tight.
Are all of your 9 lugs getting equal contact?
 
Big bore dinosaur said:
For all the weatherbys that I have Reloaded, some are picky..
Welcome to the world of high pressure curve ..finicky 2 tune.
I like to keep the case tight to the chamber and set my full-length die on the tight side to reduce case head expansion. But on the other hand I got better accuracy by not camming the bolt with a piece of brass that is a whisker too tight.
Are all of your 9 lugs getting equal contact?
Click to expand...

Vanguard is a standard 2 lug bolt action...made by Howa in Japan.
 
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