They used to be very highly regarded in the .mil/.gov world. Haven't heard much from them in the last decade or so.
www.usoptics.com
Agreed. They were considered to be very reliable, high-end scopes at one time, very heavy, stout and with good adjustments.
A friend has 3-4 of them and he had the best/worst buying experience with one. He received one with an MOA reticle that wasn't calibrated. He called them and they immediately sent a replacement scope, on his word he would return the first one, which he did, but first...
He received the replacement within a couple days and it too had an MOA reticle was not calibrated. He called them again and they sent a THIRD scope out to him, again before receiving either bad scope back. The third scope they sent was perfect and he still has it. I have never seen such a stark contrast between "quality control" and "customer service". I can't believe those scopes passed QC, but they did him right and he had a working scope within about 10 days of his first complaint.
I used to set up a lot of rifles for students, and kept a few USO rifle levels in stock. They are/were nice solid units, easy to recommend and some sort of level is critical for good precision at long range. One day, I put three of them on the same rail and found that none agreed and only one was near correct according to my Starrett machinists level. I contacted USO and they told me that the devices were not intended to be absolutely correct, but to be used as a comparative device to ensure the same rifle position shot-to-shot on one given rifle. One was at least a half-bubble away from the others, but, according to USO, not defective.