About RifleScopeCalc

RifleScopeCalc publishes calculators and buying guidance for riflescopes and precision shooting optics. The premise is that most optics money is wasted on the wrong number rather than on the wrong brand: rings that will not clear the objective, magnification the exit pupil cannot support, a scope that runs out of elevation before the distance you actually shoot.

What we cover, and what we do not

Optics and the hardware that mounts, levels, protects and supports them. Riflescopes, red dots, low power variable optics, prism sights, magnifiers, spotting scopes, rangefinders, binoculars, tripods, rings, mounts, bases, anti-cant levels, torque wrenches, mounting and lapping kits, bore sighters, lens cleaning, caps and covers, chronographs, and the rests, bags and paper targets used to confirm a zero.

We do not cover firearms, ammunition, reloading components or anything requiring a licensed dealer, and we never recommend or link them. There are no "best rifle" pages on this site. Where a ballistic figure requires a load, we name the load the figure assumes, because a drop table that does not say what it assumes is useless. That is a disclosure about the arithmetic, not a recommendation.

Where the numbers come from

Every figure on this site falls into one of two categories, and we label which on every page that carries both, because a reader looking at a table cannot otherwise tell them apart.

Sourced figures are exact arithmetic or published formulas. One minute of angle subtends 1.047 inches at 100 yards, which is trigonometry rather than convention. One milliradian subtends exactly 3.6 inches at 100 yards, by definition. Exit pupil is objective divided by magnification. Twilight factor is the square root of magnification times objective. Gyroscopic stability uses the Miller Twist Rule as published. Trajectory uses the published G1 standard drag function, integrated numerically, which is the same reference the ballistic coefficient on your box was measured against.

Shooter convention is everything the hobby has settled on without a standards body behind it. The treatment of one MOA as one inch at 100 yards. The eighth of an inch of clearance under an objective bell. The advice to be two inches high at 100 yards. Ring height names, which are marketing rather than measurements. Typical dark adapted pupil diameters, which are population ranges. All of it is useful and none of it is a specification.

What we refuse to estimate

Several figures in this subject are simply not published, and the honest response is to say so rather than to invent something plausible. The outside diameter of an objective bell is the clearest example: manufacturers publish the lens diameter, and the housing around it is what actually contacts the barrel. So our ring height pages return a range and tell you to measure your own, rather than a single confident number that would be wrong for many scopes.

The same applies to total elevation travel and exact eye relief, which most makers omit from their listings. Where a figure is not published, our spec sheets leave the row out instead of filling it in.

We do not test products

We do not test optics in person and we never claim to. Every recommendation is researched from manufacturer specification sheets, published optical and ballistic formulas, and the recurring themes in verified owner reviews. Any site claiming hands-on testing of forty riflescopes across a season is telling you a story, and we would rather be useful than impressive.

What we do instead is match products to arithmetic. The ring height pages only ever recommend rings that actually clear the objective in question. The low light pages only promote optics with the objective diameter being discussed. A recommendation that contradicts the page it sits on is worse than no recommendation at all.

How products get into the catalog

Every product is verified live against the Amazon Creators API, and every returned title is read against the product the page claims it is, because a search hit is not proof of a match. Prices, images and links are taken from that payload rather than typed by hand, so a card cannot carry an invented price or an invented photo.

We reject a great deal. Searching almost any scope term returns a wall of near-identical listings from sellers with no service path, and they outnumber the established makers. A scope is a precision instrument that has to hold zero under recoil for years, and the warranty is a material part of what you are buying. Our rejection list, with the reasoning, lives in the site source rather than being quietly dropped.

Safety

Confirm your firearm is unloaded, with the action open and the chamber visibly empty, before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, and know what lies beyond your target. Follow the law where you hunt and shoot, including rules on land access, permitted cartridges and seasons. Nothing on this site is a substitute for a qualified gunsmith where one is needed.

The site as it stands

264 of the reference pages here are computed rather than written, which is why they agree exactly with the calculator that produced them. A further 48 spec sheets are generated from verified catalog data. The roundups, comparisons, reviews and guides are written, and they carry the same labelling rules as everything else.

Questions, corrections and disagreements about a number are all welcome: get in touch. If we have a figure wrong we would rather hear it than keep publishing it.