Mastering the Art of Scope Bedding: Techniques for Precision, Hunting, and Tactical Rifles
Updated: 4 days ago
Quick answer: bedding a scope means setting the tube into its rings on a thin layer of epoxy so the rings hold the whole contact area instead of two hard edges. Before any of that is worth doing, the base underneath has to sit flat on the receiver. We measure that with a dial indicator. Under five ten-thousandths of an inch we true the base and lap the rings. Over that, the base gets bedded first.
Most of the scopes we find moving were mounted carefully. That is what makes this job hard to diagnose from a target. The rings were torqued, the screws were clean, and the rifle still walks its shots around the paper, because the error is underneath the mount rather than in it. We have watched a base lift more than thirty thousandths of an inch on a rifle that looked perfectly normal from the outside.
This article is the whole job in order: measure the base, decide what the measurement calls for, bed the base if it needs it, then prepare and bed the rings. Scope bedding is an irreversible modification and belongs in trained hands with the right tools. The full disclaimer is at the bottom of the page.
What Bedding a Scope Actually Fixes
The goal of scope bedding is to ensure perfect alignment and eliminate any inconsistencies caused by irregularities in the ring surfaces. When done right, bedding improves the contact area between the scope and rings, prevents scope movement under recoil, and minimizes stress on the scope tube. This is particularly valuable for high-recoil rifles, long-range precision shooting, and hunting rifles that must perform reliably in extreme conditions.
Start With the Base, Not the Rings
Almost everything written about scope bedding is about bedding the scope into the rings. That is the second half of the job. The first half is the joint underneath it, and on a factory rifle it is usually the one doing the damage.
Here is why. A receiver is machined, ported, polished and heat treated, and the surfaces a base sits on end up slightly out of line with each other. The base itself was made in a different factory to its own tolerances. Bolt the two together and the base is sprung into a shape neither part intended, and it pulls on the action every time you tighten it. Bed a scope into rings sitting on a twisted base and you have built a very precise mount on a crooked foundation.
Measure It Before You Decide Anything
Put a dial indicator on the base. Front screws tight, then loosen and tighten each rear screw while you watch the needle, then swap ends and do it again. On a good rifle you will see a couple of thousandths. We have seen more than thirty thousandths of lift at the front of a base on a rifle that looked perfectly normal from the outside, and you could watch it move by eye as the rear screw came down.
That reading decides the job. Under five ten-thousandths of an inch, the base is close enough that truing it and lapping the rings will get you where you need to be. More than five ten-thousandths and lapping cannot correct it, because lapping opens a hole that is already larger than the tube. That is the point where bedding the base stops being an upgrade and becomes the actual repair.
Bedding the Base, Step by Step
1. Strip and prepare. Base off, receiver and base degreased with acetone, and the underside of the base scuffed with 150 grit so the epoxy has something to key into. Do not touch that scuffed surface afterward.
2. Release agent on everything you intend to take apart again. A thin coat on the receiver and on the screws. Skip this step and you have permanently glued a base to a customer's rifle.
3. Mix a small amount of epoxy, roughly a quarter inch by an inch of each part, dyed black. Rub it into the base rather than laying it on, and keep it fairly thick.
4. Decide where the base sits before you draw it down. On a long range rifle, leave a little extra under the rear so the base sits slightly high at the back. The scope stays level to the target, the barrel points up, and the shooter gains usable elevation out of the same optic. On a hunting rifle working inside five hundred yards, draw it down flat.
5. Draw the screws down gently until the base bottoms and epoxy squeezes out, then back the screws off so there is no tension on it at all. This is the step people get wrong. The base has to lie in wet epoxy under no load. Cure it under tension and all you have done is set the same twist you were trying to remove.
6. Clean the squeeze-out while it is still wet. Dry cotton swabs first, then swabs and white vinegar, which dissolves wet epoxy and will not hurt the finish. Dry it, then check with a flashlight. Missed epoxy is far harder to deal with the next morning.
7. Cure overnight, then pop the base off with light prying and trim the flash. Open the screw holes with a #28 drill by hand, degrease them, and chase the threads with a 6-48 tap. The front hole is usually blind against the barrel thread, so finish that one with a bottoming tap.
8. Deal with the front screw. It sits over the barrel threads, and on a lot of actions it bottoms out on them before the base is ever clamped, which means the screw is tight while the base is loose. Take ten to twenty thousandths off the tip, about half a thread, and polish it. That polished screw is the identifiable front screw for the life of the rifle.
9. Install with blue thread locker on clean threads and torque to the base maker's number. Then put the indicator back on and check your own work. The lift you measured at the start should be gone.
Once the base sits flat, the rings and the scope are the second half of the job, and that is what the rest of this article covers. If you want the measurements and torque numbers that go with a standard mount rather than a bedded one, our scope mounting and torque spec reference covers every published figure we could find.
The Second Half of the Job: Bedding the Scope Into the Rings
Prepare the Rings Before Any Compound Goes In
Before applying any bedding compound, it’s essential to ensure that the scope rings are properly prepared. This step creates the foundation for a precise, long-lasting bed.
Lap the Rings to Contact, and Know Where to Stop
Lapping is a crucial step for achieving optimal alignment and contact between the rings and the scope. A slight misalignment, even within a fraction of a degree, can place stress on the scope tube, affecting accuracy and potentially damaging the scope internals over time. Here is how we lap:
Mount the rings on the rifle's rail or base and snug them down to ensure alignment.
Use a quality lapping bar that matches the ring diameter (e.g. 1-inch or 30mm) and apply a small amount of lapping compound to the rings.
Gently move the lapping bar back and forth until you achieve even contact on both rings. Aim for at least 90 percent contact. The hard stop is the ring halves still closing on the tube with an even gap. Past that point you are opening a hole that is already larger than the tube, and bedding is the answer instead.
Roughen the Bedding Surfaces
After lapping, it’s essential to roughen the inner surfaces of the rings where the bedding compound will be applied. This step creates a better bonding surface for the bedding material and helps it adhere securely.
Use a fine abrasive paper or a Sandblaster with a light touch to create a textured surface.
Be careful to avoid over-roughening, as excessive material removal can cause uneven bedding.
Choosing and Mixing the Bedding Compound
Choosing the right bedding compound is key. We prefer Acraglas or Marine-Tex, as both are durable, stable, and suitable for high-stress applications. Here is a quick guide to each:
Acraglas: Known for its flowability and ease of use, making it ideal for applications where you need a thin, even layer.
Marine-Tex: This compound is slightly more robust and is a good choice for heavy-recoil rifles or applications where temperature stability is a priority.
Pro Tip: Leave the left-over bedding compound next to the project. This will let you know when the bedding compound is hardened and you mixed it properly.
Release Agent Is Not Optional
Before applying the bedding compound, coat the scope tube and any areas of the rings that shouldn’t bond with a quality release agent. This step is non-negotiable; if you skip it, you risk permanently bonding the scope to the rings. Kiwi Shoe polish or Acra release work well.
Apply a thin, even layer of release agent to the scope tube. Make sure it’s fully covered.
Bedding the Scope Into the Rings
With the scope prepared and release agent applied, it’s time to bed it into the rings.
Degrease scope rings: Apply Acetone on the roughed surface where the bedding compound will bond with the scope rings.
Apply the Bedding Compound: Place a thin layer of the bedding compound on the roughened inner surfaces of the rings. Avoid using too much; a small amount is sufficient to achieve a tight fit without creating excess cleanup.
Position the Scope: Gently lower the scope into the rings, making sure it’s correctly aligned along the barrel. Tighten the top half of the rings just enough to hold the scope in place but not so tight that you squeeze out all the bedding compound. The scope will move around quite easily on the bedding compound. Having the rifle or mount level helps prevent the scope from moving.
Clean Up Excess Compound: Use a cotton swab dipped in vinegar or acetone to clean up any excess bedding compound before it sets. Be cautious near any finishes, as acetone can damage certain coatings.
Curing and Final Cleanup
Let the bedding compound cure according to the manufacturer’s instructions. Once it’s set, remove the top halves of the rings to inspect the bedding job.
Inspect the Bedding: Look for an even, consistent layer of bedding compound. Any gaps or irregularities could cause stress points on the scope tube.
Final Cleanup: Remove any release agents on exposed surfaces. Finish up by wiping down the scope and rings to ensure no residue remains.
When It Does Not Come Out Right
Even experienced gunsmiths can encounter challenges during the bedding process. Here are a few advanced troubleshooting tips for common issues:
Misalignment with Barrel: Occasionally, you may find that the scope and barrel are not perfectly aligned. This could be because of many things but the big two we see is the scope base is drilled and tapped incorrectly on the receiver, or there is a curve in the barrel that is so bad that the windage is maxed out on the scope. If you encounter this, Bedding can correct the issue. Alternatively, some gunsmiths use offset inserts to create perfect alignment or bases that have adjustable windage ability.
Uneven Bedding Compound Cure: If one part of the bedding compound didn’t cure properly, it may be due to insufficient mixing or environmental factors. Reapply the compound, ensuring it’s fully mixed, and maintain stable temperatures during curing.
Three Things People Believe About Scope Bedding That Are Not True
Myth: Bedding isn’t necessary for high-quality rings. While premium rings may have better tolerances, even the best rings can benefit from a properly executed bedding job. Bedding ensures full contact and can enhance stability, especially on high-recoil rifles.
Myth: Bedding only matters for precision rifles. Scope bedding can improve consistency for any firearm, whether it’s a hunting rifle, a tactical setup, or a benchrest gun. Any time you can increase surface contact and reduce stress on the scope, it’s worth the effort.
Myth: bedding is a substitute for measuring. It is not. Bedding a base you never indicated is guessing with epoxy, and it is how a shop ends up charging for work the rifle did not need. The measurement decides the job.
A Five-Minute Check You Can Do Tonight
Unload the rifle and check it twice. Then take a bright flashlight and look along the seam where the base meets the receiver, from both sides, front and back. A gap you can see is a gap that is being closed by the screws every time they are tightened, and a feeler gauge will tell you roughly how much.
Next, look at the gaps between the ring halves. They should be even side to side and front to back. A ring pinched down harder on one side than the other is either sitting on a base that is out of line or was tightened in the wrong order.
Neither check replaces an indicator, and neither one tells you to reach for epoxy. What they tell you is whether the mount is worth a closer look before you start blaming the barrel or the ammunition.
What This Costs at Redleg
Mounting a scope and lapping the rings to contact is $200. If the indicator says the base needs bedding, that job is $375. Bedding the base and the rings together is $550. Those figures are labor only. Rings and bases are quoted separately, because the hardware runs from a forty dollar set to a four hundred dollar one-piece mount, and pricing them into a package would be guessing.
Worth knowing before you buy hardware: cheap rings usually cost more at the bench, not less. Tolerances that are not held mean the indicator finds more error, the lapping takes longer, and the job climbs a level. The customer who saved three hundred and fifty dollars on rings often pays it back in labor.
Frequently Asked Questions
What is scope bedding?
Scope bedding means setting the scope tube into its rings on a thin layer of epoxy so the rings support the whole contact area instead of two hard edges. The same idea applies one layer down, where a base is bedded to the receiver so it stops fighting the action every time you tighten a screw.
Does bedding a scope actually improve accuracy?
It removes a cause of inconsistency rather than adding accuracy on its own. A scope that is being twisted by its mount moves under recoil, and a scope that moves gives you a new zero every few shots. Fix that and the rifle shoots the group it was always capable of.
Should I bed the base or the rings first?
The base, always. Rings sitting on a twisted base are a precise mount on a crooked foundation. Measure the base with a dial indicator before you decide anything else.
How do I know if my scope base needs bedding?
Put a dial indicator on the base, tighten the front screws, then loosen and tighten each rear screw while you watch the needle. A good rifle shows a couple of thousandths. We have measured more than thirty thousandths of lift on a rifle that looked perfectly normal from the outside.
What is the cutoff you use to decide?
Five ten-thousandths of an inch. Under that, truing the base and lapping the rings will get you where you need to be. Over it, lapping cannot correct the error, because lapping opens a hole that is already bigger than the tube, so the base gets bedded.
Should I bed my scope in the rings, or just lap the rings?
Lapping is the first answer and it is enough on most rifles. Bedding is what you do when lapping has run out of room, when the rings are low quality, or when the rifle recoils hard enough that contact area matters more than convenience.
Is scope bedding permanent?
The epoxy in the rings is permanent for practical purposes. That is why release agent on the tube is not optional and why this is not a first project. A bedded base can be removed, but the bedding stays with the base.
Will bedding my scope void the warranty?
Bedding does not touch the scope's internals, but any epoxy on a tube is a modification, and some makers take a dim view of it. Ask your scope maker before you commit, and understand that the ring is the part doing the gripping either way.
What epoxy do you use for scope bedding?
Acraglas Gel or Marine-Tex. Acraglas flows better and suits thin, even layers. Marine-Tex is tougher and holds up better under heavy recoil and temperature swings. Both are stable enough for the job.
Can you really use shoe polish as a release agent?
Yes. Neutral shoe polish is what sits on our bench, and a purpose-made release agent works just as well. What matters is that it covers everything you intend to take apart again, including the screws.
How long does the epoxy have to cure?
Follow the maker's time, and give it overnight before you disturb anything. The useful trick is to leave the leftover mix beside the job. When the leftover is hard, your mix was right and the bedding is set.
Do expensive rings still need lapping or bedding?
Often less, sometimes not at all, but the price on the box is not a measurement. Premium rings are held to tighter tolerances, which usually means less lapping. Cheap rings are where we find the most work, because the error the indicator picks up is larger.
Why does my scope base lift when I tighten the rear screws?
Because the receiver and the base were machined in different places to different tolerances, and the two surfaces do not match. Tightening one end pulls the other off the receiver. That lift is the error bedding removes.
Can bedding fix a base that was drilled crooked?
Sometimes. If the misalignment is small, bedding can take it out. If the holes are badly off or the barrel has enough curve to run the scope out of windage, the answer is an offset insert or an adjustable windage base, not epoxy.
What does scope bedding cost at Redleg?
Mounting and lapping is $200. Bedding the base as well is $375. Bedding the base and the rings is $550. Those are labor only, and rings and bases are quoted separately because the hardware ranges from forty dollars to four hundred.
Can I bed a scope myself?
If you have a dial indicator, a torque driver that reads in inch-pounds, the right taps and the patience to let epoxy cure without touching it, yes. If you skip the release agent you will glue a scope into its rings, and that is the mistake that ends the project.
Bring Us the Rifle, or Bring Us the Question
If your rifle used to shoot and now it does not, the mount is the cheapest thing to rule out and the most common thing we find. Our accuracy diagnostic is $150. We shoot it, measure it, and hand you a graded report with the price of every option before you decide anything.
Call Redleg Company at 507-677-6007, or bring it in. 430 Main Avenue, Chandler, Minnesota. Monday to Friday, 9 to 5. Full service list and current pricing at www.redlegguns.com/services-offered.
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Disclaimer: Informational Purposes Only
The content provided in this blog post about bedding scopes is for informational purposes only and should not be considered professional advice. Firearm modifications, including scope bedding, should only be performed by qualified individuals with proper tools, knowledge, and experience. Improper modifications or handling of firearms may result in damage to your equipment, void warranties, or compromise safety.
Redleg Company assumes no responsibility or liability for any injuries, damages, or legal issues resulting from the use or misuse of the information presented here. Always follow manufacturer guidelines, firearm safety protocols, and consult a professional gunsmith if you are unsure about any aspect of your firearm or its accessories.
By engaging in any activities discussed in this blog, you agree to do so at your own risk.
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