.257 wby mag with magpro powder

dotts1530

Beginner
Aug 7, 2011
2
0
I want to reload 115gr Nosler Bt with AA Magpro powder. I know 67.8gr is max but want to know if anyone has used this load and pushed max with good results.
 
I emailed Johan Loubser (Accurate/Ramshot's sn. ballistician) about that cartridge a while back and here is what I got back from them:

Caliber: .257 Weatherby Magnum.
Barrel length: 26”
Powder: Accurate -- MAGPRO®.
Bullet weight: 100grains.
Start load: 66.2 grains (3100 – 3200 ft/p/sec)
Maximum load: 73.5 grains (3500 – 3600 Ft/p/sec).
Bullet weight: 110 grains.
Start load: 64.3 grains (3000 – 3100 ft/p/sec)
Maximum load: 71.5 grains (3375 – 3475 Ft/p/sec).
Bullet weight: 117 grains.
Start load: 63.0 grains (2975 – 3075 ft/p/sec)
Maximum load: 70.0 grains (3275 – 3375 Ft/p/sec).
Bullet weight: 120 grains.
Start load: 60.0 grains (2900 – 3000 ft/p/sec)
Maximum load: 68.9 grains (3200 – 3300 Ft/p/sec).
 
dotts1530,

Welcome to the forum. Trust you get the answer you are looking for. QuickLoad projects that you are well within a safe range with that charge. When I've loaded for the 257 Wby Mag, I've not used MagPro, primarily because if I gave the recipe to the owner, they wouldn't be able to find the powder here in Canada. Consequently, I've used other powders. However, the pressure curve is very good, giving a nice, sustained push to the projectile throughout the burn. I would think it would be an excellent powder with the 115 grain BT.
 
Welcome to the forum! Magpro is some of my favorite stuff in the WSM's. Seems like a screamer in the 257W as well! Good luck, let us know how the range tests go. Scotty
 
Sounds good. Looking forward to seeing what the big 257 does with Magpro. Data sure seems pretty good. Scotty
 
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