Here's my entry.
Remington 700 in 300 Winchester Magnum. Calibrated loads of 62gr H4350, 180gr Sierra Game King loaded in Remington brass and WLR primer. no filler. from a bench using pack as rest.
.62 group size, .59MOA had to shoot at a steel backer so there's lots of paper tearing, but the holes in the steel are what is measured.
had to fix the photo