Scope slides forward, help me stop it

[Ramson222]

The vortex 0ptic on my 450 bushmaster keeps sliding forward. Ive determined that the mount screws are coming loose with recoil. I was thinking of using loctite on the screws. Should I also loctite the scope tube into the rings?

[tradbear55]

Blue loctite. Problem solved.

[Petrol & Powder]

Is the scope sliding in the rings or are the rings coming loose from the base?

If the scope is sliding in the rings the first place to look is the quality of the rings. I've seen more than one set of economy rings that were not sized properly.
If the rings are good, the next place to look is the uniformity of tension. The rings should be tightened from both sides equally. Remove the upper half of the rings, remove the scope, clean the scope body and the inside of the rings with alcohol or acetone (be careful with acetone, it will remove some paints) After the rings and scope are clean and free from oil, place the scope back in the rings and align the scope as needed. tighten the rings incrementally from both sides as you go. The goal is to spread that clamping force equally as you tighten the rings. When the rings are tight, there should be an equal gap on both sides. If both sides bottom out before the rings are tight, the rings are too large.

If the rings are too large you can replace the rings or shim them with something. Unless you intentionally want to tilt the scope, the shim material needs to go completely around the scope. Shimming rings is a last resort and it is better to replace the rings if possible.

[cwlongshot]

I like rubber cement myself. It cleans easily and generally fixes the issues.

I have had two different scope in different rings on my RARR in 450 and never a problem. Im now using WARNE rings and a old 30mm Tasco EURO CLASS Scope.


PP has some Excellent advice!

CW

[bosterr]

I cured scope sliding in rings by glueng them. I currently use Loctite clear vinyl, fabric and plastic glue to mount scopes on handguns larger than.22 up to .475 Linebaugh and .50 Alaskan. I've used Duco Cement and even vinyl arrow fletching cement. What squeezes out can be easily removed by a wood toothpick. Just a very thin coating on each ring half is sufficient. I clean the rings and scope with either brake clean or acetone. Whenever possible I use 3 or even 4 rings on a scope. Sliding scopes were a chronic problem for me and haven't had a single problem since.

[waksupi]

Use fingernail polish on the screws. Go to a sporting goods shop, and get a rosin bag. Rosin the inside of the rings well. Some rings are a poor fit. If you have a gunsmith around, they may have a ring lapping tool. Easy to use, if a friend has one.

[pietro]

.

I always lap the inside of the rings with emery paper wrapped around an appropriately-sized wooden dowel, loaded with oil.

There are thin materials that can then be used to line the inside of the rings for a sure grip on the scope.

Then, I clean all the screw threads of both each screw and it's threaded hole with lacquer thinner - then let it evaporate before applying a drop or two of blue Loctite (red plastic bottle) to each set of threads.

After the reticle's aligned vertically and all screws tightened, then to set the threads, I place a squared-off drift pin atop each screw head and give each a solid smack (no love taps) with a heavy hammer before going back over each screw and give them that last partial turn that couldn't be had w/o the tapping/setting.

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[country gent]

I lapp the mounted rings with a brass bar and fine compound. then a light coat of resin or blue Loctite in them install caps (Once lapped they are dedicated front and back ) here you need to work quickly so the resin/Loctite dosnt set up before your done. One scope is squared and eye relief set, remove cap screws and paint fingernail polish or blue lock tite on threads and under side of head to hold. Remember on these small screws even blue requires heat to break loose. Another trick on heavy recoiling rounds and rifles with "double recoil" ( ***, semi autos) is if possible add a third ring to the mount. On flat tops not an issue and most bridge mounts can be done.
I find the lapped rings resin/Loctite normally holds for most.

[KCSO]

I also use fingernail polish as if you want to remove something it will come loose without beggaring the screw heads.

[Ramson222]

I do degrease the rings scope and screws. Maybe it's the rings. I have these rings https://www.amazon.com/Vortex-Optics...ow+pro&sr=8-11
Going to loctite everything in place, before the next range trip.

[country gent]

I would set them on rail in place and lap them lightly with a rod. this brings them into alignment breaks up the smooth surface in the rings and gives a better bite. the light lapping only takes a few mins to do and makes a big difference

[Walks]

I spent more then a dozen years working for 2 different Gun Stores.

Mounted hundreds of scopes, never had one come back loose. Unless the Blasted Customer fiddled with it.

I degreased every screw and screw hole with Gun Scrubber. Tightened base screws with BLUE Loctite. Mounted lower rings, screwed down tight, if necessary, due to design. Cleaned inside of rings and scope body with Gun Scrubber. Put scope in rings, tighten down rings evenly as you align the scope. Once the scope is aligned evenly and set in place, I tightened the rings until the screws started to "harden" up, gave an extra 1/4 to 1/2 turn.

Mounted my Mark X in .375H&H that way using Redfield bases & rings in 1978, 2500 rds later it's still solid as a rock.

Doesn't matter what Base/Ring Combo you use as long as you do it RIGHT. And I didn't even use Loctite on the Rings.

I know a lot of folks lap their scope rings, and maybe their setup requires it.
But if you make the inside of the Rings smoother, then it just makes the set up easier to slide back & forth. I've never had to do it. If your Base/Ring combo requires it for alignment, then something is wrong with the Bases, Rings or how they were mounted.

I think if you have to shim anything, get another mounting system.

[M-Tecs]

Brownells Rosin has worked well for me for or heavy recoiling rifles. With heavy recoiling handguns 3 or 4 rings tends to work. Same for the tactical rings with more surface area. Not sure if the still make them but in the earlier days of scoped handguns the made a tube cover that mounted between the bell or the turret housing. With your flat top you can mount the ring so it goes against the turret.

Loctite 222 or nail polish will prevent the ring screws from loosening but the question is why they are loosing? Something isn't right.

[winelover]

All good info on mounting/mating scopes and rings. However, don't overlook the type of metal the rings are made of. I personally, dislike aluminum rings. Never had any luck with them. They are usually provided with the less expensive scopes. Vortex does offer aluminum rings.

Recently, ordered a Vortex Crossfire II (1 x 4) with lighted reticle. Midway was running a promotion with free set of Vortex Picatinny rings...............when they arrived, I noticed that they were aluminum. Installed them, anyways. Didn't have any 30 mm steel QD's on hand. Mounted the scope on my 9mm CZ Scorpion. Jury is still out and whether, they will hold zero and not slip. If they do, I will replace with Leopold or Warne, offerings.

Winelover

[Shawlerbrook]

Great advice above. Loctite or finger nail polish on the screws. Degrease, lap and rubber cement the inside ring surfaces.

[JeepHammer]

I'm usually the odd man out, so this is how I learned in the Marine Corps...

Measure tube to make sure it's round, and to ensure your ring saddles will fit snugly when lapped.
Rings bigger than tube allow very little surface area contact, usually just a 'Stripe' at the bottom.
Better to start with a slightly undersize ring than an oversize ring.

Mount rings on rail (picatinny or whatever),
Lap rings true with each other. You are 'Machining' the rings to fit specific spots on your specific mount, the rings are no longer 'Generic'.

Unless it's a 1 piece ring/mount, 100% of rings will benefit from lapping, and even on 1 piece mounts lapping verifies the rings are aligned.

Lapping also makes rings ROUND so they fit the ROUND tube (load bearing surface), rings are RARELY round.
Witness mark caps/rings so the front ring gets back on the front, and the correct cap goes back on the correct saddle. Witness marks also tell you left from right.

For example, one punch mark on front saddle/cap on the left side, two punch marks on rear saddle/cap on the left side gets saddles & caps back on in the correct location, and orientation.
If it's a numbered picatinny rail, scratch the slot number on the under side of the saddle so it gets back into correct slot.

A 120 to 180 grit lapping compound leaves a good surface to grip paint on the tube.
Do NOT polish the ring saddles or clamps.

Use rings that have two screws on each side, if one screw fails... Redundancy.

Use a torque wrench/screwdriver to install clean screws into clean holes, use loc-tite.
DO NOT over torque! Don't 'Guess'.
You WILL oval the tube without a torque wrench of some kind.

Non-lapped rings can bend the tube, curved or 'S' shaped, over tightening clamps can oval or 'Cats Eye' the tube.
Tape, lining material are poor excuses for workmanship and proper fitting...

[Spooksar]

I'm usually the odd man out, so this is how I learned in the Marine Corps...

Measure tube to make sure it's round, and to ensure your ring saddles will fit snugly when lapped.
Rings bigger than tube allow very little surface area contact, usually just a 'Stripe' at the bottom.
Better to start with a slightly undersize ring than an oversize ring.

Mount rings on rail (picatinny or whatever),
Lap rings true with each other. You are 'Machining' the rings to fit specific spots on your specific mount, the rings are no longer 'Generic'.

Unless it's a 1 piece ring/mount, 100% of rings will benefit from lapping, and even on 1 piece mounts lapping verifies the rings are aligned.

Lapping also makes rings ROUND so they fit the ROUND tube (load bearing surface), rings are RARELY round.
Witness mark caps/rings so the front ring gets back on the front, and the correct cap goes back on the correct saddle. Witness marks also tell you left from right.

For example, one punch mark on front saddle/cap on the left side, two punch marks on rear saddle/cap on the left side gets saddles & caps back on in the correct location, and orientation.
If it's a numbered picatinny rail, scratch the slot number on the under side of the saddle so it gets back into correct slot.

A 120 to 180 grit lapping compound leaves a good surface to grip paint on the tube.
Do NOT polish the ring saddles or clamps.

Use rings that have two screws on each side, if one screw fails... Redundancy.

Use a torque wrench/screwdriver to install clean screws into clean holes, use loc-tite.
DO NOT over torque! Don't 'Guess'.
You WILL oval the tube without a torque wrench of some kind.

Non-lapped rings can bend the tube, curved or 'S' shaped, over tightening clamps can oval or 'Cats Eye' the tube.
Tape, lining material are poor excuses for workmanship and proper fitting...

I agree except the loctite on the rings, about the time of the last Mammoth on earth I was a Millwright Apprentice, one of the instructor taught us that Loctite was invented because people forgot how to probably torque down bolts. In 45 years of mounting scopes I’ve never used Loctite nor has a scope come loose. Torque the rings in stages, evenly after proper lapping and fitting.

[cwlongshot]

I agree on locktite on ring threads. I never will or have had the need to lock tite them. Way back I too was taught to use nail polish as it was cheap and probably before lock tite was invented but surely before it was so wildly known.

I do and will for ever completely clean and de grease base holes and screws then torque WITH RED LOCKTITE bases in position!!

CW

[JeepHammer]

I built rifles for field Marines, including my own and we used loc-tite.
It's your choice, but if you beat rifles like field Marines do, it's not a bad idea.

I don't use loc-tite on the tube, just top side screws.
Thumb knobs on mounts need to be loosened with a coin (or P-38) so day optics can be switched for night optics or removed so iron sights can be used if the optics are damaged.
That's not a requirement in the civilian world.

Science warning...

It's coefficient of friction and surface area that holds the tube in the rings.
There is also a temperature factor.

When the ring, saddle in particular is too big, the sides of the saddle don't grip the tube when it's clamped.
This is why an undersized ring lapped to size is preferable.

A slightly rough surface grips the tube better.
The tube will have paint, and a slightly rough, tight fitting saddle will simply grip better than a smooth painted ring saddle.

A steel receiver, with a steel mount should probably have steel rings.
Not an absloute requirement on the rings, but you shouldn't ever put an aluminium mount on a steel receiver.
On average, aluminum expands twice as much as steel, and since the rail is screwed down, it will have to deflect (bend) in some direction which will cock rings askew and try to bend the tube.

If you do this long enough, you will find just room temp is enough to cause issues with aluminum.
A set of rings tightened in a warm room, then taken out in the cold will contract, screws can become loose since they are steel.
Install in air conditioning and take out on 100°F day and the aluminum will expand, even more so when you shoot and the upper warms up.

These thermal cycles (hot-cold) will loosen screws in aluminum.
If it's aluminum rings, I usually use loc-tite on cast or extruded (cheap) rings.
The more expensive forged/billet usually have better threading in the holes, and better screws, and you can often get away without loc-tite, but it doesn't hurt anything.

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As for loc-tite, (that's Loctite brand name, some other brands have different properties)

The 'Red' is high strength stud and bolt 'Locker', which takes heat to get loose, and will often take the threads out of aluminum, brass, and it takes many platings/finishes off also.
It a pain to clean off, and when it gets 'Crusty' it will strip the threads off small fasteners, so if you used 'Red' use heat when you disassemble.

The 'Blue' is 'Medium' strength, and usually doesn't cause issues with anything but the cheapest rings.
The heat from a soldering iron will ensure it comes loose with basic hand tools without damage even on the cheapest aluminum.
This isn't the high heat version.

The 'Purple' is the stuff to use for most firearms applications.
It backs out with hand tools, doesn't need heat, and doesn't corrode aluminum.

The 'Green' is 'Creeping', really thin out of the bottle to get into really small spaces, and it will creep into the threads of a nut/hole while the screw/bolt is installed.
Strength is between 'Blue' and 'Red', usually takes heat to easily remove the fastener.
(And it gets EVERY WHERE, the 'Creep' isn't limited to the screw/hole you were aiming at...)

Everything but the 'Purple' is hard to clean off, the 'Purple' comes off with a thumb nail when you need to clean threads for reapply. Running a CLEAN screw into a hole will often strip off old Purple (field conditions) and new purple will stick to old purple, but your torque reading might be off with 'Goop' in the threads.

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Generally, when I mount optics someone is paying me for it...
But I'm not a 'Home Builder', I get a lot of rifles that have been problems for someone.

I start with hanging the barrel/receiver between centers on an end mill table and using a probe to see if the barrel is cocked in the receiver.
No sense in mounting another optic when something like receiver face, barrel shoulder or rail/mounting holes are skewed.
I fix what I find.

Nothing fundamentally wrong,
Install rails/ring and lap the rings.
Start with reasonably quality rings a little undersized and lap to fit the tube.

Center the bore on a plumb line (receivers lie, so do scope turret caps) and then center the optic on the plumb line.
Gravity never lies.

Make sure the optic reticle is centered right/left (windage) and rotate the optic until the vertical reticle line is centered vertically over the bore, vertical reticle line on the plumb line bisecting the bore.
No way to screw it up when gravity is your standard.

*IF* the vertical reticle line WILL NOT line up on the plumb line, then the rings have the optic cocked to one side.
This is the time to work on the ring to rail mount until it does.
Since the rings *Should* be witness marked, you know which is front/back, right/left,
Shave the bottom of the ring to get the vertical reticle line in position over the plumb line.
Rings are cheaper than mount rails, and it's usually the rings that are 'Wrong'.

Install caps that were witness marked for right/left, front/rear when reamed or lapped.
Then add an anti-cant device while the action/upper is locked in the vice centered on the plumb line.
Now the ACD is true and not relying on the receiver top, rail or optic reticle adjustment cap.
Again, gravity doesn't lie...

I get the rifle when it shoots 'Right' under 100 yards, and 'Left' at 200 yards, this is a sure sign the optics are not aligned with the bore.
Shooting 'High-Right' and 'Low-Left' (discounting normal ballistic drop) is a sure sign the barrel is cocked in the receiver or the optics are canted (or the owner isn't getting the reticle square, canting the rifle).

Do what best suits you, but after I get rings fitted to a specific rifle (rings being the least expensive part that gets changed if you switch optics to another rifle),
I'm going to use a drop of loc-tite to ensure the optics stays where I spent time & energy putting it.

[cwlongshot]

EXCELLENT INFORMATIVE POSTING!!

Figures it takes a JEEP guy to simplify things to common language information!!

THANK YOU for your service Marine!!

CW