Sometimes it seems that nothing is more confusing to a new gun owner, and even some old hats, as installing a scope on a firearm. The sheer number of choices and options in optics alone are enough to write books about, and the ways to actually put the scope on the gun are even more complicated. This article will attempt to clarify choices and make the novice gun owner’s job in choosing a way to mount a scope easier, while at the same time illuminate the myriad of options for any gun owner. What You Need to Know (or Find Out) When you start looking to mount a particular scope on your firearm you need to know certain things before you start shopping for mounting options. To begin with, you’ll need to know your scope’s objective diameter, usually the last and largest number in a scope’s specifications. This will be used to determine the clearance needed for your scope. The next important measurement you’ll need is the scope tube, and thus what ring diameter is required by your scope, usually 1″ or 30mm. You need to know what mounting system your rifle is equipped with; receiver grooves, Picatinny rail, Weaver dovetail base, or nothing at all. The type of firearm you have and in some cases, what barrel type and contour, will also impact what mounting system you will need to use. A flat-top AR-15 has vastly different ring requirements than a Remington 700 with a tapered barrel. The Basics The most common setup used, and inquired about, for putting optics on a long gun is mounting a traditional magnified rifle scope to a traditional bolt action rifle. Let’s use this setup to explore the basics of putting a scope on a rifle. Traditionally the scope is held onto the rifle by “rings” which are clamped around the body of the scope. In turn the rings are attached to some sort of “base”, which are normally then attached to the rifles receiver or action. To add to the confusion, there are many variations of all of these components. There are ways mount a scope that combine some or even all of these individual components. (An example would be mounting an EOtech HWS to an AR-15 rifle, where the scope has an integral mount that does not require rings, and the rifle has an integral rail that does not require a base.) Bases The base is the part of the system that allows the attachment of the scope rings to the rifle itself. Traditionally bases are attached to the receiver of a firearm by some sort of screw or bolt. Some rifles have built-in bases that are integral to the firearm. Bases are usually specific to the make and model of firearm for which they are designed, and most are specific to the type of rings that can be used with them. Rings The Ring you select must be the same inner diameter of your scope’s tube diameter, which makes sense. The rings clamp onto the main tube of the scope, so they must be the same size. Most scopes are 1 inch in diameter and so are most rings, but there are many 30mm scopes and rings, and a smattering of other choices, such as 34mm. The other end of the ring attaches to the rifle’s base, so it too must be compatible with that particular base. The important thing to remember is to match the rings with the scope and the base. Ring Height Scope rings come in varying heights to vary the distance from the scope’s centerline to the firearm’s base or receiver. The different ring heights allow you to mount scopes with different objective sizes and also to mount the scope in the proper place for a quick and proper cheekweld. Rings normally come in low, medium and high heights. There are extra low and extra high variations from some manufactures. Ring height is one of the most confusing options for new gun owners. The traditional mantra is that scopes should be mounted as low as possible without the front of the scope, the objective bell housing, touching the barrel. Also bearing in mind the need to the back of the scope, the ocular bell or eyepiece, to clear the bolt handle. The thing most often ignored in this choosing scope ring height is the need for the scope’s height to match the shooter. When the rifle is shouldered quickly, the scope should be at the correct height to look through it, without any additional movement on the stock up or down to get a good view through the scope. Remember though that there is no “perfect” ring height that would suit every person, as each person’s physiology is a little bit different. There is a standard ring height worth noting, as it gives an excellent starting point for 90% of gun owners.
Ring Height According to Leupold
|In this illustration from UTG, Ring height is measured with “C”|
- 50mm objectives will almost always use HIGH rings in a given style. In certain instances, such as with extremely heavy barrels or some makes of firearm, EXTRA HIGH rings may be necessary.
- 42-45mm objectives will almost always use MEDIUM rings in a given style. In certain instances, 45mm scopes may require HIGH rings.
- 40mm objectives will almost always have enough clearance with LOW rings in a given style, though MEDIUM rings will give slightly more clearance, particularly when using a barrel with a thicker shank portion or a heavier contour.
- 28-36mm objectives will almost always use LOW rings in a given style. Again, in certain instances of a heavy barrel or heavy shank portion of a custom barrel, MEDUIM rings may have to be used, but LOW rings will almost always suffice.
- 20-24mm objectives will almost always be able to use LOW rings, but in some cases may also use EXTRA LOW rings. In this instance, bolt handle clearance of the eyepiecel will come into play more so than objective / barrel clearance and should be carefully considered.
- Use low 1″ Rings for up to a 38mm Scope Objective
- Use medium 1″ Rings for up to a 40mm Scope Objective
- Use high 1″ Rings for up to a 44mm Scope Objective
- Use extra high 1″ Rings for up to a 50mm Scope Objective
- Use 30mm Low Rings for up to a 33mm Scope Objective
- Use 30mm high Rings for up to a 44mm Scope Objective
The mission of Cheaper Than Dirt!'s blog, "The Shooter's Log," is to provide information-not opinions-to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!