Have been working through the original document and the graphs Pete posted and came up with this.
32 Gr Ballistite (3 Dram Equiv.)
Breech - 2.9 Tons per Square Inch (UK, Long) = 6496 psi (pound force per square inch)
2 1/2" - 2.2 Tons = 4928 psi
6” - 1.2 Tons = 2688 psi
12” - .81 Tons = 1814 psi
18” - .33 Tons = 739 psi
24” - .21 Tons = 470 psi
83 Gr No. 4 Black Powder
Breech - 2.26 Tons = 5062 psi
2 1/2" - 1.96 Tons = 4390 psi
6” - 1.26 Tons = 2822 psi
12” - .9 Tons = 2016 psi
18” - .33 Tons = 739 psi
24” - .21 Tons = 605 psi
SO once again, the pressure is falling rapidly with either Black Powder or Smokeless and is quite low by 18"
|