[Paul Harm]

You would have to send shells in to be tested. You won't get smashed primers with shotgun shells - we're working with a lot lower pressures than rifle pressures. I personally feel if I'm using a mild 12ga load it will be safe in the 10 because the chambers are bigger having more surface for pressures to work against. Get the free reloaders handbooks from Hodgdons or Alliant and compare loads in different gauges using the same powder and you'll see how pressures go down as the gauge goes up even with more powder. That 19gr load of Red Dot with a 1 1/8oz of shot is a old 12ga target load. The 23gr load was with Green Dot, not Red Dot. You're going down a road many argue against - they like only tested or manufactures loads. There aren't many with the 2 7/8 10ga so many of us do what we feel is safe. The faster burn rates are usually for light target loads. Less powder is needed. We have a number of loads here. Maybe stay with them till you get a little more experience. Promo and RD are the same, Promo is cheaper. I like the 19grs of Promo/1oz of shot or 23grs of GD/1oz of shot. But then I'm only shooting clay birds and those work fine without recoil.