Hello Darl_S

Thanks for the reply.

I'm going to try a few of my "heavy" bullets for my 16 ga Vogelbüchse. They are the correct dia with 2 lube grooves. They weigh about 650g (1-1/2 ounce) and I'll try a starter load of FFg. I should know within 2 pairs of shots if its going to improve grouping.