It i designed to be fired even from choked and rifled.
It acts like an under-gauged.
The Green Lightning (Heavy Field Short Magnum) 12GA 2¾” and 20 GA 2¾” is one of the most famous hunting slugs ever. You will be surprised about the tremendous knockdown power and the penetration. It is usable for long distances. The Green Lightning (Heavy Field Short Magnum) is the best combination of power and accuracy you can get.