Tks. for the heads up on the powder buring, Smoke. If the crimps are not heavy enough, or initial pressure seating the wads isn't high enough, it's difficult to get the slower burning powders to ignite.

That's why Ed's is using Fed 439 or maybe it's 239 (whichever is the right number) primers - the hottest shotshell primers available, anyway. Powder compression with the wads is important as well and difficult to get with plastics. I think rather than total plastics, a plastic cup on the powder, then 1/2" fibre and card wads are the answer to get the powder buring correctly. The plastic wads come out of the case too easily, I think. Reduce loads to start, of course, when changing anything. Normal seating pressure with card and fiber wads was 50 pounds.

I've some blue Dot I could try SR7625, which shot very accurately in my 12 bore double as well as SR4756 - right to 1,500fps chronographed using 'cupped' .684" balls (466gr. in WW, and 482gr. Pure). I think I got to 1,400fps with 7625. In the 12, they are b oth very slow burning powders for normal 1 1/4oz loads. Since I was shooting the lighter round balls, I got quite good downrange results with those powders.

Lyman has some data for blue dot and the rest in their shotshell book with .690RB's and maybe 500gr. Breneke's or some-such slugs and their 525gr. sabot slug that fits the red wads perfectly. Differeing years have different data, but most of it runs only to 1,500fps max. Of course, with 500gr. bullets or balls, that's quite enough and matches 1890's elephant loads for the early ball guns shooting 7 drams.

Everyone should try that load at least once, if your stock is up to it strength-wise. It's a bit hairy in a 7 1/2 pound 12 bore, though.