It is a more common occurrence than you might think. You have your new rifle or new rifle scope, new rings, and a fresh mount. You did all the right things during the installation. At the range, you fire your first several groups and notice somethings odd. Your riflescope seems to be slipping forward.
Rifle slip or rifle creep is an issue that can occur with any scope, any rings, on any rifle. There usually isn’t one issue that causes the problem. Gunsmiths who routinely mount scopes are aware of the problem. Almost every seasoned shooter and gunsmith has a few tricks up their sleeve to prevent slip or creep.
Taking a systematic approach to riflescope creep or slip is the tried and true method. A search on the internet returns hundreds, if not thousands, of suggestions for eliminating scope creep. Many of them work well. Some of them we don’t recommend for various reasons, and you should avoid a few at all costs. In this article, we will look at a few in each category and make some recommendations.
Exactly What is Riflescope Creep?
To understand riflescope creep, you need a bit of knowledge about physics and what happens when you pull the trigger on your big bore hunting rifle. Those first few milliseconds after the primer ignites are the critical period for riflescope creep. Let’s look at the sequence step-by-step.
Primer Strike and Ignition
You pull the trigger, the firing pin strikes the primer, the powder ignites, and the rifle goes boom! That is typically what happens. As the burning powder expands, it pushes the bullet down the barrel toward the muzzle. Isaac Newton taught us that for every action, there is an equal and opposite reaction. You feel that reaction as recoil and the resulting thump or push on your shoulder.
Recoil as Acceleration
Think of recoil as the entire gun accelerating backward as the bullet accelerates forward. The backward acceleration is the equal and opposite reaction part of the equation. Your rifle wants to go from a dead stop to the same speed as the bullet in an instant.
Getting Everything Moving Together
Everything on your rifle must move together. As recoil takes hold and shoves the rifle backward, all those attachments to your rifle, including the riflescope, must catch up. Often, the forces in play will try and keep the riflescope in the same place. The result is a slight bit of movement of the scope rings backward on the scope tube. This movement appears as the scope creeping forward in the rings.
Tiny Movements Add Up Over Time
Normally, scope creep or slippage doesn’t happen on one big change. If you get a huge change, say a one-eighth-inch slip on one shot, you have much different problems. Riflescope creep may only cause movements in the thousandths of an inch range with each shot. The effect is cumulative over time but may take many shots to be noticeable.
So, How Do You Remedy Riflescope Creep?
Like many other problems in shooting sports, there is rarely a single fix for every problem. Just like there are different causes, different approaches to riflescope creep often yield successful solutions.
Start at the Beginning
The beginning is always a great place to begin. Without sounding facetious, if you don’t start correctly, you can’t end correctly. A poorly done riflescope installation will make eliminating rifle creep and other issues almost impossible.
Rings and Bases
Start with the bases and rings. All too often, the problem isn’t with the rifle, scope, or rings. The problem is the alignment of the scope rings and bases on the rifle receiver itself. The bases must be securely mounted and aligned on the rifle’s action. Rings and bases not properly aligned make it almost impossible to get the rings to grip the scope tube properly, often resulting in scope creep
Getting It Straight
You must make sure that the rings and bases align with each other, that the mounts align with the rifle’s bore, and that the connection between the ring bases and the rifle’s action meets factory specifications.
Some tools can help you complete each of these tasks with precision. Unfortunately, some of these tools are expensive. The cost of the tools to do the job properly is why many shooters opt to have a gunsmith perform this part of the scope mounting job.
Making it Tight
Every scope ring manufacturer has specifications for mounting its rings and bases. Part of these specifications includes the torque required to set the bases in place properly. Failing to use proper torque settings can cause multiple failure points. Always follow the manufacturer’s recommendations to the letter.
To Loctite or Not?
Again, you should defer to the manufacturer’s recommendation on using thread locker on the ring bases and screws. These recommendations differ widely and, in maintaining your warranty, always follow what the manufacturer suggests.
Ring and Scope Fit
Another area where you can have problems resulting in riflescope creep is the fit between the rings and the tube of the riflescope. The diameter of your riflescope tube dictates the size of your scope rings. However, different manufacturers have different machining tolerances that often affect fit.
The alignment of the holes in your receiver, the quality of the manufacturing of the rings, and the tolerances of your scope manufacturer all affect scope and ring alignment. Getting all these incremental alignment issues corrected seems insurmountable. However, there is a solution. Lap your scope rings.
Lapping Rings – Yes, or No?
To lap or not to lap is a question that gets hotly debated. There are arguments for and against that deserve consideration. Our bottom line is that honing or lapping your scope rings solves more problems than it creates and should be a part of every scope installation.
Mainly because lapping your scope rings creates a surface that is the best possible mount for your riflescope. Lapping smooths and polishes the inside of your scope rings, making them flat and true. This polishing also creates rings that align better with the tube of your scope. Better ring-to-tube surface mating means a tighter fit that resists creep and slippage.
Making the Final Fit
After you align the bases and rings and lapping the rings too true them, it is time to make the final fit of your scope. In truth, if you have already performed the right steps, your scope should snuggle down into the rings nicely.
Considering the very tight tolerances that most of today’s manufacturer expect, you scope rings should have a firm grip on your riflescope tube. There are several things to remember as you finish the installation of your riflescope.
Check the Eye Relief on your Scope
If you don’t understand eye relief, you need to do a little research before you do the final install on your rifle. Getting the eye relief right will prevent having to remove and reinstall the scope later. Anytime you remove and reinstall a riflescope, you introduce the chance of scope creep after the reinstall.
Understand the Manufacturer’s Recommendations
The manufacturer of your scope rings and your scope may have specifications and recommendations on mounting the scope in the rings. The most important specification that both ring manufacturers and scope manufacturers make is the torque used on the scope ring screws.
From the perspective of the ring manufacturer, the material from which they make the rings and screws determine the proper torque for the screws. Tightening screws to the proper torque ensures that the screws and the ring material provide the best strength overall.
Over-torquing the screws can lead to some problems.
- Screw damage – The easiest way to damage screws and threads is to apply too much torque. The threads on the screw or in the receiving block can strop away or distort. On a riflescope ring, even one of four screws with damage can weaken the system enough to cause a scope to creep or slip.
- Broken screws – It is quite easy to break a screw by applying too much torque. Likewise, an over-torqued screw is easier to snap or break from the force of the rifle recoil. An over-torqued screw is much like a spring under too much tension. The broken screw no longer contributes to the strength of the ring system, and the scope can begin to creep.
- Ring deformation – Over-torquing the screws on a ring mount can twist or deform the ring from its specified shape and dimensions. This ring deformation can affect the scope tube, leading to scope creep or even failure of the scope’s adjustment processes.
Keeping all the adjustments, screw torques, and alignments in the manufacturer’s specifications is the best way to get the performance you want from your riflescope and ring mounts. Making sure the specifications of your parts are all in line prevents having to put one part out of specification to keep other parts in line.
What You Shouldn’t Do
The internet search returns hundreds of websites and forums with advice on sopping or preventing scope creep or slippage. We have seen many different ideas for preventing scope creep. Some may have merit, but we advise you think twice before taking such advice. We do not condone or recommend any of these methods and suggest that you not attempt such scope creep remedies.
Many comments on forums suggest an easy solution to scope creep is to shim the scope inside the rings. The solutions offer many different variants on the materials and methods for making or installing these shims. Some of the more popular suggestions include:
- Tape – This concept to control scope creep is to line the scope ring with something that will grip or adhere to the scope tube to stop the movement. The suggestions include
- Electrical tape
- Duct tape
- Double-sided adhesive tape
Today’s scopes and rings are manufactured to such tight tolerances that adding anything with any appreciable thickness risks damaging the scope, the rings, or both as you tighten the ring screws to proper torque.
- Silicon – There are several suggestions seen on the internet that advise coating the inside of your scope rings with a thin layer of silicone sealant. According to the adherents of this idea, a thin layer of silicon between the scope ring and scope will do several things.
- The silicon creates a tight non-slip bond between the scope rings and the scope tube that prevents scope creep and slippage.
- Moisture between the scope rings and the scope tube can lead to corrosion and other damage, leading to scope creep.
- The thin layer of silicon acts as a cushion between the scope rings and the scope tube. Supposedly the silicon layers act as a shock absorber during recoil.
Some other firearms and riflescope writers advise readers to over-torque the screws on their scope rings to stop scope creep or slippage. These commentators argue that manufacturers routinely over-engineer their products, and over-torquing may even be expected.
Nothing could be more wrong. Manufacturers engineer and build their products to tight tolerance and specifications. These specifications are published to ensure that end-users obtain the most consistent and reliable operation properly. Using a product outside these specifications often yields unexpected and unreliable operations.
Mix and Match Assembly
Most manufacturers recommend that components of scope mounts and rings not be mixed and matched. Scope ring and mount sets should be used together as they are packaged. This caution about mixing parts goes to the screws provided with the scope rings and mounts. Despite their small size, most scope rings and mounts are intricately engineered to precise specifications. Changing screws or other parts can change how the parts work together and seriously impair the way the scope rings and your scope work together.
Taking the Creep Out of Your Scope
There is no real secret to stopping scope creep. For the most part, you can stop most scope creep by:
- Buying the highest quality scope rings and mounts possible.
- Mate your scope with the right rings. Scope manufacturers often recommend which style and manufacture of scope rings work best with a particular scope.
- Follow the manufacturer’s recommendations about scope base and ring installation. Keep everything in specification.
Today’s high-quality scope rings, bases, and mounts should not, when installed properly, allow scope slippage or creep. A riflescope that starts to creep is a symptom of a bigger issue with the installation of the scope mounts, bases, and rings.