Will they let use this - 945 (315 x 3) grains of hard cast .60 cal "buckshot.":
Dixie Tri Ball 3"
Bullet Name: Dixie-Tri Ball 3"
Bullet Weight: 315.00 grains
Bullet Diameter: 0.600 inches
Muzzle Velocity: 1100.00 ft/sec
Ballistic Coefficient: 0.085
Line of Sight Above Bore Axis: 0.75 ins
Zero: 0.0 Inches at 30.0
Crosswind: 0.00 mph from 0 degs
Temperature: 70 deg F
Altitude: 500 ft
Firing Angle: 0 deg
Cant Angle: 0 deg
http://www.dixieslugs.com/home.html
The Tri Ball will smoke most anything on earth.