[taxcontrol]

Pressure wave has a lot to do with burn speed.
Max pressure allowed determines max load.
Another vector in the pressure wave has to do with how well the bullet seals.

but the biggest factor I find is the level of legal defense the publisher is willing to accept. IOW, different companies have different max loads because they are either aggressive or defensive in their recommendations.

[MileHi]

but the biggest factor I find is the level of legal defense the publisher is willing to accept.

Ye, I have noticed that over time. But in my post you see that one has a "starting load" above the other "+P" load. And the powder guy said the bullets were that much different. They are both 125 gr JHP so I don't buy it.