Patterning navy double 12 gauge

[Garbear34]

70 grains powder, 1 1/8 oz #8 shot. 4 over powder from cereal box i cut with a punch put over the powder 2 cards ovee shot. 25 yds. Looks ok. Was short on time. Also tried round ball at 25 yard pistol outdoors range. High and to the left.

 

[Blackpowderart]

Looks very good, try 3 cards under shot
And /or bump up the powder a little more to see if you can get more even spread. A very good pattern any way you cut it, but it's a little heavy on the lower half

 

[BillinOregon]

I would be thrilled with that pattern-- even from a modern unmentionable. Is that a greased pattern board? I have seen them but never used one. Looks like a very nice range you have there.