Powders change enough over time to make it risky to use old data with new powders, like anytime something is changed when working on loads, one should start near the beginning again.
<br>Plus I believe the more accurate pressure measuring systems have made them realise some pressures were not what they thought they were.
<br>I know my load in the 243 with IMR4350 now appears to be about 4 grains over max, according to the books out now, and yet never had a problem with it before.
<br>So someone must have learned something, or too maybe like you say, there are liability laws and they don't dare take any chances, I am sure the good doctor when able will add more to this for you.
<br>Bill
