Smurf, if this will help you ...
* No 1 Remington 1879 50-70 with a bore of 501 x 507, 1:26 twist
Lee 515-450F 457gr 1:20 Starline CCI BR2 Swiss FFg 70gr 0.075 Felt 1263 Avg 13.8 SD
Best I could do at 1000yds - 7 ring with the receiver ladder sight -
It being a windy day when I was shooting 1000yds and about 3 feet to the right of the target, I managed my 'Infamous Miss' on a 4" swinger