Ahsan Ahmed
CGN Ultra frequent flyer
I use 20 ga. for deer [slug] and turkey, as well as small game and upland. The 20 is not less of a shotgun, just lighter load. Actually, its flatter shooting, and faster than 12.
The trajectory of a 20ga slug, particularly a saboted slug will be flatter in comparison. However, it won't be any faster given the same cartridge length, load type and shooting distance involved.
Who cares about flatter shooting when talking about birds.
I would much rather prefer a bird gun to shoot 50/50 patterns.