If I understand well, are you saying the 5.9 load is above max because the 1095 velocity is higher than the IMR data of 1060? If so, how dangerous would it have been to go all the way to 6.3gr, almost a half grain?
Yes, there is a 1:1 correlation between speed and chamber pressure (within the loading range). So when you shoot a new-to-you load, you can use your chrono and the Max Velocity to warn you.
Going to 6.3gr would be a
huge leap. Powder burns more efficiently at higher chamber pressures. Which is to say it may take 0.3 or 0.4gr to make the difference at the LOW end that you can achieve with 0.1 at the HIGH end of the load range. (It's NOT linear, it's a curve.) So what you'd want to do is drop back and check out 5.8gr. If those were low, then you could shoot a 5.9gr again. I'm not saying my numbers are gospel,
I'm only reporting what my chrono told me. I have very reason to believe my test was done correctly, but on another day I might get another answer.
Additionally,
Velocity and
Chamber Pressure loose their 1:1 correlation somewhere north of Max Load. So even if you have a chrono it's not going to be of much help. Notice that
Pressure zooms upward while
Velocity flattens out. More than one gun has been blown up chasing "that last 10 fps".
Bottom Line.... once you pass the Max Load all bets are off. If you need more velocity, then the thing to do is change your powder. Max Load then is like the red line on your car engine tachometer. You don't bury the tach in the red zone just to "see what happens" or to go 3mph faster. No, you shift from 3rd into 4th. So moving on to the next slower powder is equivalent to shifting gears.
Follow all that ?
