In fairness, recall these guys are shooting at torsos, not at golf balls. As I've eluded above, it's not uncommon for shooters to be able to print a smaller group on a large target than the size of target they could actually hit, in other words (since that sounds ridiculous), a guy can hang a 24" target at 1,000yrds and print a 12" group in the middle, but the 16" target right beside it will induce a boatload of misses. Hitting a deer in the heart at 600yrds is easier than hitting a prairie dog. It's all point-of-aim-reference - hitting the center of something big is far easier than hitting something small. A dozen or so buddies and I used to do an "egg shoot" copied from the PredatorMasters Convention Egg-shoot, a Grade A Large Egg is about 1.7" across by 2.2" tall, glued to golf tee's, seated in a target rack, so firing at 150yrds, you're talking a hair over 1MOA. Any of these guys and their rifles can print a sub-moa group on larger targets, most of them in the .5-.6moa ballpark, but hitting a target which is about the same size as your group is an entirely different game. Guys print sub-moa groups on my big steel all of the time, myself included, but the game is completely different when the target shrinks.
Unertl is a hard one to sneak past autocorrect, drives me nuts when "inertial" drops in, since not enough folks are familiar with Unertl to make the re-correct back in their head.