Weatherby Select .257 Weatherby Magnum 100 Grain Spitzer Boat Tail Brass Cased Rifle Ammo 20 Rounds. s personal favorite. Travels 3605 fps (100 grain bullet) giving you the flattest trajectory of any 25 caliber rifle in the world. Suitable for long-range varmint shooting but ideal for big game hunting (depending upon bullet weight). Specifications for Weatherby Select .257 Weatherby Magnum 100 Grain Spitzer Boat Tail Brass Cased Rifle Ammunition: Manufacturer: Weatherby Caliber: .257 Weatherby Magnum Number of Rounds: 20 Bullet Type: Spitzer Boat Tail (SBT) Bullet Weight: 100 grain Cartridge Case Material: Brass Package Type: Box Primer Style: Centerfire Package Contents: Weatherby H257100IL Select 257 Wthby Mag 100 Gr Hornady Interlock 20 Bx/ 10 Cs Weatherby H257100IL: Select .257 Weatherby Magnum 100 Grain Brass Cased Rifle Ammo 20 Rounds