I only mention this scope because the title of your post was a "Good" Varmint Scope, but I have doubts that mounting this 26" tube is even possible on an AR15. And then there's the problem that Unertl Optics ceased producing these fine scopes several years ago and the market for 2" calibrated head model puts the price in the $1000 to $1500 range and rising.
Hopefully you have at least seen one of these beasts as they are a bit difficult to describe. But the first impression of anyone seeing one for the first time is usually one of a fragile piece of junk. But nothing could be further from the truth. In fact after having used at least 7 or 8 brands of rifle and pistol scopes, the Unertl will hold a zero better than any other and the optics are unsurpassed.
I keep trying to imagine the sight of an AR15 with one of these beauties resting on top, but I suspect it would turn more than a few heads. But if you could get one mounted it would make a fine varmint sight. I believe the 2" aperture model comes in powers from 15 to 36 and the optics are the finest to be found on any telescopic sight. (Unertl is a precision optics company making lenses for many applications and is still in business but no longer manufacturing rifle scopes)
I realize the price does sound a bit high, but from the time they ceased to be produced, prices have steadily risen and I suspect that will continue into the future.
So there you have it. A "Good" varmint scope. And quite possibly a Great investment as well.
fprefect