No, there are no comps (at least as of yet) People on here have just started experimenting at these ranges after a certain Aussie (Harry) ruffled a few feathers by informing us of his achievements. Initially there were major doubts with regards to his alleged groupings but a few have gone on to achieve similar. The biggest variable is the wind, even a gusting .25mph breath of wind is enough to ruin a group.
Re- max range, How long's a piece of string? I guess its down to what the wind conditions, Ft/lb, FPS, pellet weight and bc allow, I reckon 100 yards is pushing the boundaries of sub 12ft/lb paper target shooting. You can see what Geoffs 70FPE Condor is capable of though..