Yes, the Big Sky 3-9x36 scope from Sightron is likely one of their most memorable mistakes ever. Not because it is a lackluster or weak scope, as you might be guessing, but for precisely the opposite reason: is one of the premier scopes of its type on the market today, but Sightron hasn't bothered to let anyone know. This scope was originally marketed as a rimfire / airgun scope, not presented as part of their mainstream big game hunting rifle line. Sure, the original SII 3-9x36 was a beautiful little scope, but hardly limited to rimfires or air rifles. It was one of the most practical all-around hunting scopes available, but few people knew about it.

While I am picking on my friends at Sightron, calling their Big Sky scopes “SIIB” or “SII Big Sky” scopes was another blunder. Big Sky scopes have optics equal to, or in some case better than, the most costly scopes out there, including different glass than the SII line. Calling them SIIB scopes is a grave injustice; it makes the scope sound modestly "improved," more like a Microsoft service pack or a bug fix instead of a new line of scopes.

The SIIB 3-9x36 AO has many things going for it. The eye relief is consistent at about four inches throughout the range, making it suitable for the hardest recoiling big-game rifles. The internal adjustment range is excellent at eighty inches, letting you mount this scope without worries on most rifles where a 40 or 50 inch internal adjustment range scope will not quite work.

Despite its adjustable objective, this great looking scope will not overwhelm most sporting rifles. It is 12.8 inches long and weighs 14.5 ounces. The very nature of a 36mm objective lens suggests that this scope is better-equipped to handle extreme recoil than larger, heavier lenses would, because the mass of larger lenses inflicts more force on scope tubes under recoil acceleration.

Like all Big Sky scopes, this model has superb image quality, Sightron's ExacTrack adjustment system and is fully multi-coated.This scope comes with a threaded sunshade extension and see-through scope caps, a couple more goodies that Sightron does not mention on their website.

What Sightron has here is the optical equivalent of a thousand dollar Swarovski Z3 3-9x36, with twenty-two extra inches of internal adjustment and an adjustable objective for less than half the price. This scope can be considered idea for a broad range of applications from your 300 Win. Mag., your muzzleloader, your slug gun and, yes, a deluxe rimfire or high-performance air rifle.

This is likely Sightron's most magnificent mistake. It is one of the best scopes offered today in the 3-9x platform, regardless of price. Sightron has never felt the need to mention this to anyone, though, for reasons beyond my amoeba-like comprehension level. The Big Sky 3-9x36AO is a spectacularly good scope!