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.

Read my latest post in 220 Swift thread. But yes Varget and 175-200 fps slower. It’s a pisser.

I have had a similar experience with AA2015 in my .223. It was accurate, but about 150fps slow with the same charges listed. Thing is, it showed pressure signs when I tried to increase the charge to bring the speed up, so I just went back to H4895.

I am not sure about DHN's AA1680, but in the case of your AA2015 the problem is that it was manufactured in 3 different countries. Israel, Czech Republic and now in Canada. The Canadian powder is a different burn rate than the previous powders but was never changed in any load book or burn rate chart

That would figure. It's hard to trust anything put out in the load manuals as anything more than a suggestion.

As long as it's accurate and consistent, I don't worry much about making "book." Barrels are female, anyway.

Too many variables. Case volume. barrel length. seating depth, bore dimensions all make a difference. If the data dose not also show pressure how do you know if it shoot out of a SAMMI Standard test barrel? It might not have had rifleing in the barrel. That why you some times see data with the bullet seated deep in the case. It gives them free fps because the usable case vol. is decreased that causes higher pressures that = higher fps. Powder manufacturers are there to sell powder not give the most accurate load.

I hope you start learning to look at posting dates before commenting on every thread. You've drug up a bunch of old threads with mostly useless comments, why?