Hi Steen, this bullet leaves the barrel at 2275 feet per second and has a muzzle energy of 3736 ft lbs.
Stay safe & have a great day!

2275 fps see ****
Underwood Ammo Xtreme Hunter Specifications
Brand: Underwood Ammo
Brand Family: Rifle
Bullet Type: SC (Solid Copper)
California Proposition 65 Compliant: Yes
Chemical Concern: Nickel (Metallic)
Caliber: .45-70 Government
Case Material: Nickel Plated Brass
Packaging: Boxed
Energy: 3736 ft-lbs
Grain Weight: 325 gr
Lead-Free: Yes
Packaging/Packing: Box
Primer: Boxer
Reloadable Case: Yes
Rounds Per Box: 20
****Muzzle Velocity: 2275 fps

Full specs below:
This ammo is for cartridge size .45-70 Government +P.
The bullet is made from Copper.
The diameter (caliber) of this bullet is 0.458.
This bullet weighs 325 grains.
This bullet leaves the barrel at 2275 feet per second.
The ammo case is made from Nickel Plated Brass.
This ammo is a proven round for hunting.
The bullet in this product does NOT contain lead.
This round is designed to be supersonic and travels faster than the speed of sound.
The muzzle energy of this ammo is 3736 ft lbs.
This product has been designed to be an effective choice for the ultimate in self-defense applications.
The bullet in this product has a Sectional Density, (SD) of 0.221337176200737. SD is the ratio of an object's mass to its cross sectional area with respect to a given axis. It conveys how well an object's mass is distributed (by its shape) to overcome resistance along that axis.
This ammo IS SAFE to use in a suppressor.
The bullet in this ammo has a ballistic coefficient (G1) of 0.23 - Generally, the higher the coefficient, the more stable the projectile will be in flight.
Each box of ammo contains 20 loaded pieces of ammunition.
This ammo is manufactured by Underwood Ammo

Hi Steen and welcome. Muzzle Velocity is 2275 Feet Per Second & Muzzle Energy is 3735 Foot Pounds. Cheers and stay safe!