I was messing with AA1680, 20 grain Hornadys in my .17 Hornet, for the first time. The max charge in the Hornady handbook is 12.4 grains. At that charge, case signs indicated low pressure, chronograph showed average 2000fps for 15 shots. There was room for a little more powder, but not enough to indicate any chance of getting up where I expected. First thought, of course, was chono error, but I ran some other loads, including from other cartridges, and it read where expected. I took the powder to a friend who likes it in his K-Hornet; he got expected accuracy but velocity was 200 fps lower than his previous data showed, from a different lot. That is nowhere near the difference from book data that I experienced, and he was satisfied, so I gave him my powder. Has anyone experienced such a great difference between powder lots? I neglected to write down the lot number, but will try get it from him then contact the company.
