The science and engineering poured into modern rifles and optics borders on mind numbing. They dominate headlines, but often lost in that swell of excitement is the critical role solid mounting solutions play in precision.          

We enlisted the aid of some of the industry’s finest and asked what enthusiasts need to consider in their next purchase. A little trigonometry illustrates why their advice is worth heeding.    

Do the Math

A riflescope that suffers an unexpected 0.1-degree shift will sail point of aim 6.1 inches adrift at 100 yards (sin .01 X 3,600 inches). The figure increases proportionately with distance. 

It’s hard to fathom, even for math fans, but it underscores the importance of selecting quality mounts, bases and rings. The experts agree: Rock-solid is critical.

“Mounts are one of the more common failure points in a shooting system — rifle, ammo, shooter, etc. — so do not skimp on mounts,” cautioned Joe Freuchtel, director of optics product development at Sig Sauer. “The less complicated, in my opinion, the better, because there is a lower chance of error/problems.”

“A valuable tip to keep in mind is that regardless of the rings or mounting solution used, you need a solid, firm base, attached to the firearm,” said Bushnell Public Relations Manager Matt Rice. “If your base is not properly secured, it will inevitably affect the accuracy you are able to obtain from your scope.”

General Terms

There are some primary considerations your customers should weigh before any purchase. “One needs to ask themselves what the intended purpose is for the gun and choose mounts accordingly,” said Gary Turner, president and CEO of Talley Manufacturing. “What are priorities? Lightweight? Adjustability for eye relief? Quick detach? Scopes have become very specialized and some require specific mounting due to certain limitations — such as tube length and objective and ocular sizes.”

“Determine the best height of your rings — low, medium, high, X-high — based on the diameter of your scope, profile of the rifle barrel and the rifle’s action,” Rice added. “Generally speaking, you want to get the scope as low as possible without making contact with the barrel, while also allowing you to have the proper eye relief needed, while also obtaining a full field of view when placing your head on the rifle stock or comb. You need to make sure you have the proper clearance needed, not only over the barrel, but also items such as the bolt and the scope’s magnification ring.”

Jordan Egli, director of marketing at Burris and Steiner said, “Furthermore, consider the mounting options available, such as Weaver-style mounts or rail-specific mounts tailored to the firearm manufacturer’s specifications. For instance, if your firearm has a Picatinny rail, you need rings designed specifically for that rail. If you want rings that fit directly to a Ruger or CZ, make sure you are looking for rings designed specifically for them.”

The basics are familiar, but the industry has improved designs and harnessed advantages afforded by different materials at lightspeed in recent years. Larger, fatter and bulkier isn’t always better.

Size Isn’t Everything

“Thickness doesn’t necessarily mean more strength,” Turner warned. “All our mounts are precision machined, not cast or forged. This means that we can produce a thinner, lighter-weight mount without sacrificing strength. Mount design plays a crucial role in strength. Our QD mounts are very thin, but they are on countless dangerous game big-bore rifles and perform flawlessly.”

“While mount thickness is important for rigidity, it’s not the only factor to consider,” Egli added. “Material quality and manufacturing processes play significant roles in ensuring the mount’s durability and ability to maintain zero under various conditions.”

Rice concurs. “The thickness of the rings or mounting system does not always equate to rigidity or recoil capabilities,” he said. “Some rings are made to be extremely light by using materials such as scandium alloys or aluminum. This is often done when attempting to keep the rifle setup a certain overall weight.”

One or Two Pieces?

Receiver-mounted rails are increasingly standard on rifles today. They’ve made the addition of optics and accessories DIY simple and, according to the experts, brought with them advantages. There are, however, drawbacks.

“If your rifle has a rail, opting for a one-piece base is generally a better choice over two pieces,” Egli advised. “One-piece bases provide increased stability and rigidity, essential for maintaining zero and accuracy, especially during heavy recoil. This setup minimizes the potential for misalignment between multiple pieces, ensuring consistent performance.”

“A full-length rail has the advantage over a two-piece mount in that you can have more options for mounting points, which can aid in eye relief,” according to Turner. “That being said, on certain rifles it can put the scope higher off of the gun compared to traditional two-piece mounts. It can also be heavier and or block an ejection port on rifles where the shooter wants more room to load into the magazine from the top of the action.”

Inch-Pound Matters

“Torque is critical in clamping force,” Freuchtel emphasized. “These are going to vary quite a bit from material to material. The torque on the top rings is also critical. Once you have zeroed, if you retorque those top rings you should always re-zero.”

Egli agreed. “The torque value when mounting the base on the gun is crucial,” he said. “Over-tightening can damage the mount or rifle, while under-tightening may lead to shifting or loosening of the optic. Follow the manufacturer’s recommended torque specifications closely to achieve optimal performance without compromising integrity. We recommend using a thread locker on the bottom surface of the base.”

Lapping

The industry-wide norm of CNC machining has largely relegated lapping to second-tier status. “Lapping is a holdover from the days when most rings were cast,” said Turner. “In casting, it is more difficult to keep tolerances in spec, therefore lapping ensures a perfect round. With our rings we use a precision machining method to extremely tight tolerances. These tight tolerances mean that lapping is not required and as such lapping in some cases can actually knock a set of rings out of round.”

According to Rice it’s not quite time for the practice to completely disappear, though. “Lapping rings and bases can still be a valuable tool in order to get the best accuracy and reliability from your riflescope,” he said. “Whether this is needed will often depend on the quality of the mounting system or the fit of the base to the receiver and rings to the scope. Generally, when people discuss lapping, their intent is to help increase the amount of surface contact between the ring and scope tube, helping with proper alignment — and not putting extra pressure on one side of the ring or the other.”   

Potpourri

All material expands and/or contracts as temperature changes. Composition determines the rate and they are not necessarily equal — even between metals. In extreme cases it can apply unwanted pressure on the optic. The shifts are minute, but there are extreme long-distance shooters who demand steel mounts on a steel receiver to alleviate the variable.  

I was among the gun writers once schooled at a Leupold seminar at Gunsite Academy in Arizona, where we learned the importance of ring-screw torquing sequence. The approach is like tightening down an engine manifold. It is employed for the same reason — ensuring equal pressure distribution. Start by tightening one bolt on any outside the corner of the mount, or rings. Next, snug the one farthest away on the other side to specifications. Work your way inside, continuing the crisscross pattern until all are snugged to specification. Then, double check tightness.

The same instructor delivered another critical ingredient for rail-mounted firearms. Always apply forward pressure — toward the muzzle — on a base when tightening down. The habit applies a flush and snug fit against the forward lug, which prevents movement under recoil. 

And, according to Rice, there’s a final consideration for factory-fresh rifles. “Before mounting an optic, always check your bases,” he cautioned. “Oftentimes these may come loose or misaligned directly from the manufacturer. It’s also possible that the screws may have been overlubricated to help prevent rusting during long-term storage. It’s often suggested to remove the base, if possible, inspect it, confirm that it is making full, smooth contact and then clean off the screws and reinsert.” Torqued to manufacturer specifications, we’ll add.