I'll be interested to see where you end up with the A Frames and 4064. The Enduron 4166 is the updated version and you may want to give that a try for the long term if you have any on hand. IMR has some data for 4064 and 4166 with a 400 gr Hornady which could be a starting point when used together with the chronograph. Last summer there were several offers for 416 brass and I would be surprised if the all sold. I'll PM you on one that I didn't follow up on. I know my 416 is not much fun from the bench. Who is doing the bench work - you or your friend?
