My new group measuring system. Best 4 out of seven .  New ASSRA iron sight rule proposal. Best 10 out of 15 if the shooter is 75 or older.

I redid the target picture.  Is that better Wes?

Wes and I did shoot a best 10 out of 12, 600 yd BPC match years ago at Tacoma.  As usual, he brought a rifle he had not shot at that range before.  We had to shoot prone with the muzzles sticking out under a plywood barrier with  18" of space under it.  Only us two were shooting by that time and the spotter, an old and feeble guy didn't want to lie down close to us so he sat about 10 feet away looking through a break in the barrier.  I think Wes took too many shots that the spotter never saw and eventually gave up as he was running out of ammo. I only had 1 rifle, a 45-90 high wall, and managed to shoot 9 10s and 3 nines.  The target puller later said my group was close to 6' at 1 o'clock.  I never got that rifle to shoot that well again.

Jack, to me, it looks like the bullets are going transonic and tipping because of it.

Try adding .3 - .5 gr of powder.

Joe,
I think you were using something in 44 caliber.  You were cussing’ up a storm at Bob (not Zimmerman) who was spotting. It was the last 600 yd BP match.  The next year Chuck had arranged for the BP shooters to shoot with the high power guys. He backed out the morning of the shoot and I was the only one who showed up. I waited around for over an hour while the high power guys tried to get the 600 yd firing position ready and finally gave up and went home. No further matches were scheduled for that distance.