GunFun,
I've tried 20gr of Promo, 22.5gr of Green Dot, and 50gr of Blue Dot (this one rattles my skull). All produced poor accuracy and keyholing.
I've pushed my wads and slugs through the bore with a dowel, and the Federal 12S4 and Claybuster yellow wads are snug but not super hard to push through. They measure about 0.740" in diameter, whereas my bore is 0.732".
I've also tried Downrange yellow wads, but they are much thinner and only measure 0.720" with a slug inside. These slide down the bore freely.
I've found that recovered wads were torn up quite badly, so I decided to t