At what range are you getting those groups. By rifled slugs do you mean the ones that have rifling on them and cost $2.50 for 5 or the ones you shoot through a rifled barrel that cost $12.00 for 5? A six ' group at 50 yards is good for the cheap slugs. A 1 1/2" group at 100 yards is atainable with the expensive ones. Ask jeff223 about the rage and effectiveness of the 20 ga. He posted a nice picture on the old board of a fine buck taken with his ultra 20. Sabot slugs and rifled barreled guns with a good marksman behind them are capable of 150 yards.Cheap slugs and smooth bore guns don't have the range or the accuracy but if you are not shooting past 50 yards they are adequate.A lot of deer have fallen to them over the years, including my first 4 or 5. As for ballistics I think the 45-70 comparisson was to the Winchester partition gold.