Mueller Optics Eraticator 8.5-25x50mm Riflescope

By Chuck Hawks

Mueller Eraticator 8.5-25x50
Illustration courtesy of Mueller Optics

Mueller Optics is a relatively small, specialty firm. It was founded by Rich Schlampp, who has considerable experience in the sport optics business, having in the past partnered with firms producing optics for major brands such as Simmons.

Rich's parents were both from Germany, and the brand name "Mueller" derives from his family heritage. After the decision to establish his own brand, Rich and his buyers spent months traveling the world searching for the right components and the right factory in which to assemble them.

They eventually settled on lenses made in Japan, using a lens coating system purchased out of Germany, with the scopes to be assembled in a Chinese factory. The latter is reputed to be the best such factory in that country.

One of the top priorities was high quality assembly that would result in a low warranty return rate. Rich told me that he was confident that their Chinese assembly plant was as good as any in Japan. Having the scopes' final assembly in China greatly reduces the overall cost. This multi-national approach to scope production allows Mueller Optics to sell riflescopes of a quality equal to higher priced brands, but at a lower price.

Another strategy to reduce costs is through limited advertising. Advertising costs must, of course, be included in the price of any product. Mueller Optics prefers targeted (rather than mass-market) advertising, reviews in journals such as Guns and Shooting Online, and word of mouth endorsements from satisfied customers. The emphasis on a high quality product with few defectives means that Mueller doesn't need to add a lot of extra cost to their scopes to cover a high volume of returns. These strategies allow Rich to keep the price of Mueller scopes surprisingly reasonable.

Mueller's objective is to continue to develop new models based on the needs of hunters and sport shooters. They accomplish this by talking with thousands of shooters and customers by means of Internet forums, e-mail, outdoor shows, and spending plenty of time at shooting ranges.

Mueller Optics Eraticator scopes feature a glass etched reticle. (And no, "Eraticator" is not a typo. It is a Mueller trademark, spelled that way in Mueller literature and on the scopes themselves.) The 25mm (1") two-piece outer tubes are made of L6063 aluminum alloy. All lens elements are fully multi-coated using a new German system, with 18 layers per lens. A heavy-duty spring clip assembly insures accurate and repeatable adjustments.

The 8.5-25x50mm Eraticator scope reviewed for this article is a new model in the Mueller Optics line. It features a fast focus (European style) eyepiece, an adjustable objective for parallax correction, finger adjustable target-type windage and elevation knobs that click in 1/8 MOA increments, and a high torque power change ring. The calibrated scales concentric with the windage and elevation adjustment knobs can be repositioned to "zero" after the scope is sighted-in. Threaded metal caps and rubber seals protect the adjustment turrets.

At 8.5x the Eraticator's field of view is 18.8' at 100 yards, and at 25x it is 6.3'. The optical formula includes 10 elements, held in place by threaded positioning rings. The optimum eye relief is 3". The scope is claimed to be waterproof, fogproof and shockproof, and is nitrogen filled. The finish is matte black. All Mueller scopes come with a transferable limited lifetime warranty.

Physically, this is a big scope. It is 15 7/8" long by my measurement (19" with the lens hood in place) and the outside diameter of the objective bell is 2 3/8". The tall, target type adjustment turrets add even more bulk, as does the O-ring sealed battery case for the illuminated reticle, which sits on top of the ocular bell. Catalog weight is 20.8 ounces--it is no lightweight! The trim single shot rifle on which I mounted it felt noticeably top heavy wearing this scope.

The reticle deserves special mention. It is a super-fine crosshair with 1/16 MOA center dot. The center dot can be illuminated for use in dim light, and there are 11 brightness settings. It is powered by coin style lithium batteries. When the illumination is turned off, as it normally would be during daytime, the tiny dot appears black.

All three Guns and Shooting Online reviewers who tried this scope agreed that the reticle is capable of outstanding accuracy as long as the target can be clearly seen (as at the rifle range). Two of the three felt that it was slow to pick-up when aimed at a rodent screened by tall grass. The super-fine crosshair tended to get lost in the blades of grass. A fine Duplex type of reticle might be a useful option.

Two of us found that the reticle achieved best focus only when the eyepiece focus ring was backed all the way out. This may be a product of middle-aged eyes. The third (and youngest) shooter achieved correct focus for his eye when the ring was somewhere in the center of its travel. Perhaps an extended focusing range would be a worthwhile improvement.

This is clearly a varmint hunting scope, so I mounted it on what has become my scope test rifle, a single shot NEF Stainless Handi-Rifle in .223 Remington caliber. A Weaver base and high rings were used, and mounting was a simple and straightforward procedure. The main tube is long enough on both sides of the adjustment turret to allow plenty of latitude in positioning for proper eye relief. A Bushnell magnetic bore sighter was used for preliminary adjustment.

The first impression one gets looking through the Mueller Optics Eraticator scope is of surprisingly sharp, clear optics for so a powerful scope. Eye position is not particularly critical and optical aberrations seem well corrected. The multi-coatings do a good job suppressing flare. The adjustable objective is a handy feature on so powerful a scope, particularly since I started shooting at 25 yards and finished at 100 yards.

At the rifle range, on the 25 yard line, only three shots were required to put the final bullet in the "X" ring. I then moved to 100 yards, where I was able to adjust the scope to put the bullets in the 10 ring with four 3-shot groups, first adjusting the elevation and then the windage. There seemed to be minimal interaction between the two, which is always appreciated.

I shot groups at the minimum available 8.5x, at an intermediate 16x, and at the maximum 25x with no discernable change in point of impact. I preferred the view through the scope at about 16x, so that is the setting I used for most shooting.

Once the rifle/scope combination was dead on at 100 yards, I intentionally dialed-in 2" of elevation change and fired a test group. Bingo, the subsequent 3-shot group hit 2" higher. This shows good adjustment accuracy, especially for what is a relatively low priced scope.

I would have liked to have done some shooting at 200 yards, the maximum distance available at my local range, but there was an erratic wind gusting up to about 20 knots, and 45 grain .223 bullets are notoriously susceptible to such disturbance. Even under the not particularly favorable conditions, the very high magnification of the Mueller Eraticator allowed the little NEF Handi-rifle to deliver some of its best 100 yard groups ever. The best 3-shot group of the day measured 1/2", and the second best only slightly larger at 9/16". In fact, I think that the Mueller Eraticator will become the new default scope for my NEF varmint rifle (when the rifle is not being used to test some other scope). Rodents beware!

The Mueller 8.5-25x50 Eraticator is packaged in a long green box adorned with a red crest and the printed legend "Mueller Extreme Sports Optics." Inside are lens caps, a lens cloth, instructions, and a threaded lens hood (sun shade). Plus, of course, a very big, very powerful and very accurate scope with a green plastic oval on the left side of the adjustment turret that reads "Mueller." It's quite a package for only $249.95. Order from a Mueller dealer or direct from Mueller Optics by telephone or on their WebSite (

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