|The 577 Tyrannosaur was the largest Proprietary Cartridge introduced in 1993 by the A-Square Company as an
entirely brand new Cartridge for the A-Squire rifle.
The 750 Grain Barnes Solid Brass projectile moves at 2,460 Feet per Second,
to generate over 10,180 Foot Pounds of Energy.
If you have one of these firearms your ready to go Dinosaur hunting.