Good morning Powell, the Lee Drive Key mold comes with a loading card, some loads are far too hot to shoot for comfort like the Blue Dot load of 49 gr when all you need is 40 to 42 gr,
the HS-6 load is good around 30 to 32 gr.
What will help you with accuracy is putting a .125-16 or 20 ga nitro card below the slug in wad to give your slug a firm base, raise your slug up a bit like this:
look at the last four slugs on the right.
Your next choice is to buy yourself a Lyman 525 Slug in wad mold for $ 65 to 70 and the handles for $30 to 35 for a total of $100 plus that is if you can find one.
I take it that you have a rifled barrel and if not then with a smooth bore you need to do this test first before you go about loading a bunch:
Hoping it helps.
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