Griz44
Member
I was told that these two were the same powder. I did some research and have discovered that they are not the same, but very close. That brings me to my question. Facts come from the Hodgdon data set. They list for Winchester, Hodgdon and IMR, I assume there is some vested collective interest between the three companies.
Bullet - 165g SIE SPBT 30cal (.308)
Load is for 30-06 Springfield
H4350 59gr, 2938fps @ 49,400 CUP
IMR4350 60gr compressed, 2934fps @ 57,600 PSI
What is the advantage of a compressed powder charge?
What is the advantage of extra air in the case?
Speed for the two charges is almost identical.
Is there a factor to convert CUP to PSI or vice versa? How do the two pressures compare to each other? If one is significantly lower than the other, does this translate to lower recoil?
Bullet - 165g SIE SPBT 30cal (.308)
Load is for 30-06 Springfield
H4350 59gr, 2938fps @ 49,400 CUP
IMR4350 60gr compressed, 2934fps @ 57,600 PSI
What is the advantage of a compressed powder charge?
What is the advantage of extra air in the case?
Speed for the two charges is almost identical.
Is there a factor to convert CUP to PSI or vice versa? How do the two pressures compare to each other? If one is significantly lower than the other, does this translate to lower recoil?