This is a question both in theory and reality. I will be dealing with a cartridge that will be an improved version of the .270-.280. Necked to 6.5.
The burning rate spectrum of powders for a 140+ grain bullet in this case runs from some of the slowest powders available, to faster ones such ar RE17.
Looking closely I am struck by recommendations for some of the very slowest such as Retumbo, where you gain 40fps with as much as 15 more grains of powder being used. Really?
Obviously, with less powder ofa faster burning rate, higher potential velocities may be reached, with equal pressures as the very slowest powders. Likewise with an expanded case cartridge you can use more of the same burning rate of powder to attain more velocity. Thus you gain less heat from less powder burned, longer throat life and less recoil. I realize that 100 fps may mean very little to most, but am fully aware of what it can do at the longer ranges.
I'd welcome any experienced insights with a factual basis in this matter.
Gene S.
The burning rate spectrum of powders for a 140+ grain bullet in this case runs from some of the slowest powders available, to faster ones such ar RE17.
Looking closely I am struck by recommendations for some of the very slowest such as Retumbo, where you gain 40fps with as much as 15 more grains of powder being used. Really?
Obviously, with less powder ofa faster burning rate, higher potential velocities may be reached, with equal pressures as the very slowest powders. Likewise with an expanded case cartridge you can use more of the same burning rate of powder to attain more velocity. Thus you gain less heat from less powder burned, longer throat life and less recoil. I realize that 100 fps may mean very little to most, but am fully aware of what it can do at the longer ranges.
I'd welcome any experienced insights with a factual basis in this matter.
Gene S.