03-14-2022, 09:08 PM
LRRPF52 Wrote:Checking the mathematical engines against known pressure test data is one of the first indicators of whether the particular program is kicking out relevant data.
Hodgdons publishes their pressures, but rounded to the nearest 100psi.
A fun one to enter into the internal ballistics models is Hodgdons published data on the 90gr TNT on top of Benchmark, a compressed load.
2.200 COL
30.5gr compressed load
90gr TNT
47,000psi
Its one of the lowest published chamber pressures for a max charge in 6.5 Grendel that Im aware of. They couldnt get anymore in the case basically even with a compressed load, at the short COL that is driven by such a short bullet.
An even lower one is this:
90gr TNT
8208XBR
31.0gr Compressed
2.220 COL
42,400psi
Enter those in and see what either of the internal engines kicks out for you.
I'm going to do these, simply as a test, to see what comes out of GRT. I don't have QL so won't so that one...
love these little problems...!
"Down the floor, out the door, Go Brandon Go!!!!!"