Pglasgow
I think I mostly agree with what you are indicating. I certainly was not thinking in the terms of an obstructed barrel.
But in simple terms if you put a like amount of T7 and BH in a sealed container and lit it off the BH is certainly going to produce a bigger 'boom' thand does the T7. But, in operating theater of the a normal gun BH is not that big of greater producer of velocity than that of T7. That has been shown by several different tests.
The convinience of BH is by far the biggest factor in it's success.
[QUOTEWe know that BH209 energy on a grain volume basis exceeds that of t7 by at least 36% but we don't actually know its limit. I think it to be at least 50% more energetic than T7 in an obstructed barrel which is where the safety part comes in. When a bullet moves as it is supposed to then BH209 will operate at lower pressures than the quantity of T7 it takes to get the same muzzle energy. But when a barrel is obstructed, BH209's higher energy will result in pressures greater than an equal grain volume of t7. ][/quote]
I honestly do not know about your percentages, but I do agree with the statement.
The heaviest bullet I have shot with both BH and T7 is a .458/300 grain Nosler, Lehigh, and XTP. In those tests across a chrono the differences in BH and T7 begin to show. Moving to a 400 grain bullet would widen that gap significantly.
This is an in-complete chart showing the comparison with the 45-70/300 grain bullet. Now in real life if one of these projectiles were to reach an obstructed bore either the T7 or the BH is going to create a horrible situation.