Well, I've found out why Cougar Optics is no longer in business. When adjusting for elevation, crosshairs also move side to side. Bore sighting was a real treat.
Once I got a bullseye at 25 yards, the next shot at 100 yards wasn't even on the paper! When firing, the crosshairs shifted inside the tube so no one shot repeated in the same location.
After a frustrating hour of playing "follow the bullet hole", I left the range and replaced that piece of junk with a Bushnell Elite 4200 3-9.
Returning to the range, I found in this rifle that although 140gr Nosler Partitions go pretty much wherever they feel like going, 140gr Barnes TSX's like to stay in nice, snug groups.
Both groups are under the same conditions: sunny 92 deg temp, 4500 ft elevation, gusty winds from left to right.
(The shot on the right was a called flyer)
A final shot (not shown) landed exactly 2 1/2 inches high and directly above the bull.
There seems to be a tendency to string vertically. Is there a cure for that? The action and barrel are full-length bedded.
Overall, I'm still feeling good about the purchase. It's accurate, light and comfortable to shoot. I'm slightly disappointed to find that the scope is trash but that wasn't really too much a problem, since I was going to replace it anyway. It's a shame about the Partitions, but I don't feel particularly handicapped being limited to the TSX, especially when going after elk.