257 weatherby factory load powder?

[wvlongshot]

Can anyone tell me what brand or powder # weatherby might be using in the factory 257 wby mag loads. I'm looking at the 115 gr nos bt in particular. I tore 1 down and got the charge weight. Because I have a rifle that is a hammer with the factory load.

 

[Hal]

Longshot

Years ago they were loaded with Norma MRP. I have no idea what they use now.

Hal

 

[Fat Albert]

It's a known fact that you can't reload Weatherby Mag up to factory speed because Norma uses Swedish fairy dust mixed in with the powder.

 

[LCazador]

If the factory load works good , use the same bullet and same overall length . Then try Norma MRP if you can get it , or something similar like N-560 . Reloader 19 and 22 worked quite well for me in getting close to factory speed , and don't forget mag primers . With the exception of the 224 Weatherby , I've never been able to get factory speed on any of the Weatherby stuff , close but not quite . I'm sure there's a secret ingredient somewhere !!

 

[wvlongshot]

The speed is second on list when a sporter rifle shoots like this one does with a factory load. I'm getting ready to try a couple of different loads here when the weather cools a smidge, thanks for the info. I've been playing with a 257 stw just a bit, haven't chronoed yet, but it is pretty fast!!!!!