It is most probably due to the increased combustion area. Don't stockpile those loads if you will be using them in colder (below 40F). The performance may go into the dumper.Rastoff said:My normal recipe is:
1oz lead shot
18grn Red Dot
DRA-12 or CB1100-12
According to Alliant this will be approximately 8,600psi peak pressure in the chamber.
I've recently considered loading some el-cheapo Fed hulls. They require the CB6100-12 wad due to the straight wall. While researching the recipe for this I find that I can use everything the same (except the hull and wad), but the pressure is down to ~6,430psi.
My question is this, why is the pressure so much lower? Is it due to the straight wall vs tapered walls of the hull?
I like the lower pressure. If I can get the same performance out of my shells by switching to this then I may never go back.