not sure how many attempts I've made. 6 or 8 I think
I use a 28"x 36" white poster board with a black shingle in the center and just record pertinent info next to each shot with a sharpie for posterity.
I find it helpful having every shot on the same board.
I'm planning on a session Friday or sat or Sunday , 1 of those days at least.
I'll post a pic of my current progress .
by the way I would be quite impressed by anyone hitting that speck of a target at 100 yds. cold bore. which I plan to do!
good luck shooters
kevin