Yeah, but, only for one thing. They have lousy SD's and don't carry far. The wadcutter just didn't have the body shape to go very far.
Sectional Density has absolutely nothing to do with shape but is only the relationship between weight (mass) and bullet diameter. A 500 grain wadcutter has the same SD as a 500gr round nose or spitzer. they are just shorter.
I agree with your contention about them not going far - in air, water or animals, but that has been beaten to death on other forums and generated a lot more heat than light.
