ORIGINAL: Pglasgow
Re-read it Wolfhound. Take some time and it will all be clear to you. I don't have a 100 grain bullet in the .50 cal. The force on the bullet is completely independent of the bullet weight. All we calculated was how much pressure it takes to impress a given force onANY bullet. For a given force, it takes 4 times the pressure in .250 cal as it does in .500 cal. It is indisputable.
No. I think your generalizing this too much. Pressure increases with bullet weight. The same powder charge will produce higher pressures with a heavier bullet than a lighter one while giving you less velocity. The way your saying this is that 12,750 psi and it doesn't matter what bullet. It does matter. You used aspecific bullet weight to generate the 51000 PSI in the 25 cal.For the formula to workyou have to use the same bullet weight in the 50 cal. It's not in the formula but if you change the parameters of how you got the PSI number you change the result. The numbers don't change, but the value to someone is suspect.
What would the pressure be in the 25 cal with a 75 gr bullet? With a 120 gr bullet? You change the bullet weight in the 25 cal you change the pressure. The pressure changes so does the result of the formula.But for the result to translate over to the 50 you have to use the same bullet weight.
If I remember right you used the max pressure of the 25 cal though.
Loads for the 25-06 need to operate at peak pressures less than 51,000 psi and for 100 grain bullet, the muzzle energy is in the neighborhood of 2300 ft.lbs.
So what is the pressure for the 100 gr bullet?
This is all theoretical and it's all nice and neat but it has no real world value.
And to answer the question about the strain gauge, no Randy does not use one. He uses the software/chrono version. And no I don't think he gets good data but he'll even admit the values can be off.