Well, marching in the right direction is good. if you want, I can mail you some 16 bore WW balls.(about WW alloy)

All of the 14 bore (.684" balls I have are pure) I might have a few .675" (15 bore) balls.

The lighter the ball, the faster they can/will go and probably come to regulate your gun at some point.

The 16 bore balls are 1oz. but will penetrate MUCH more deeply than any dang FOSTER slug. I've smashed the shoulder on the 'other' side of a large bull moose with my 14 bore rifle, WW ball, after breaking ribs and traversing the body.

This last was just to say to not be concerned about the 'smaller' balls.

The 'cups' on the bottom of trap wads, or the inner cup of a steel shot wad will hold the ball centered in the bore for it's flight up the tube, delivering it perfectly centered at the muzzle. I'll send wads as well if you need them. PM me with directions if you'd like.

I'd like to get you set up with a good shooting load, Smoke.