I have spent months trying to get data that is corroborated in more than 2 places.
I want to ensure obturation of bullets for various velocities and BHN's.
Here is what I have for the most likely data.
BHN * (3*480) = min. chamber pressure to ensure obturation.
BHN * (4*480) = max. chamber pressure to ensure no deforming of the bullet.
So, I have also noticed some people say add 1 to the BHN and then use the calculation for the maximum pressure.
Some sites have stated max. BHN is BHN * (4*480)+10,000.
I have cast .270 win. and, with a BHN of 22 driven them (G.C'd) at 2500 fps with a chamber press. calc. of 42,000 psi.
The pressure is seen by the GC and the projectile is pushed forward but, what happens to the nose and body of the cast bullet.
Has anyone done testing rather than passing on some information from others?