Wby Ammo .257 Weatherby Magnum 100gr. Barnes Ttsx 20-pack. Travels 3870 fps (80 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 Wby Ammo .257 Weatherby Magnum 100gr. Barnes Ttsx 20-pack: Manufacturer: Weatherby Caliber: .257 Weatherby Magnum Number of Rounds: 20 Bullet Type: Spitzer Boat Tail (SBT) Bullet Weight: 100 grain Cartridge Case Material: Brass Muzzle Velocity: 3570 ft/s Application: Varmint Package Type: Box Primer Style: Centerfire Dimensions: 1.40 X 3.75 X 6.25 in Package Contents: Wby Ammo .257 Weatherby Magnum 100gr. Barnes Ttsx 20-pack What is Wby Ammo .257 Weatherby Magnum 100gr. Barnes Ttsx 20-pack good for? The manufacturer suggests that it is suitable for varmint.