I installed this optic on a crossman 760 air rifle.I have now shot the riffle around 500 times during target/plinking practice, and the kzfaq.infoUgkxc4K63Fd5LglDMObu7-Bgapxp_ef0W8hE scope has done well.With this optic, I have neutralized around 30 pigeons that were invading one of my buildings.For my short range air rifle, I will continue to use this scope, but will be upgrading to a more powerful scope, when I buy a more powerful air rifle, in order to shoot at longer distance.For the money I have spent, this scope has truly been a great buy.

We can all agree , if the screws are loose , it will move .

I'm not convinced because you only performed 1/2 of the demonstration. I would like to see you mount the scope to the rear, and use identical torque to see if the scope moves forward when fired.

If the screws are loose enough the scope will move backwards after moving forward and bouncing off the forward picatinny lugs. Under recoil of the rifle the barreled action has a rearward G force that the scope/mounts have to catch up to. The most force of recoil is when the bullet leave the barrel and the scope is pulled forward from recoil force of the barreled action moving rearward while the scope is static. The moving backwards is a secondary action caused by the scope mounts bouncing off the picatinny lugs in front of the ring lugs.

You have to do the test again with the scope mounted forward. It’s hard to make a claim when you only tested it one way. My guess is that a loose scope will move in both directions, which, if true, means that these tests do not provide any evidence to support your theory.

Moral to this story is-make sure all your scope mount screws/bolts are tightened to the correct torque specs and neither forward or rearward movements will occur.

The first man in the world to kick physics ass.

Only the mechanical forward stop is strong enough to withstand the initial recoil and the tendency of the scope to shift forwards. The mounting screws and friction will take care of the rearward movement of the scope when rifle hits your shoulder and comes to a gradual stop eventually. Long story short, during a firing sequence, scope wants to stay still (as all objects do) so the first force is rifle coming back and hitting the scope VIOLENTLY at the front of the scope, then scope and rifle starts moving backwards towards your shoulder and rifle comes to a stop GENTLY, and scope wants to still travel backwards but now being held in position by mounting frictional forces. So, the more violent slamming of the rifle and the scope happens at the front of the scope, that's why we always mount scopes physically resting forwards with mechanical connection. Otherwise, the screws and mounting friction cannot withstand that violent slamming. But, they can withstand the forces generated because of the rifle coming to a gentle stop on your shoulder

Objects at rest tend to stay at rest. Objects in motion tend to stay in motion.

You are absolutely correct! That is why when I use a picatinny rail, I always use rings with a locking lug in the base. That way it is impossible for the scope rings to creep backwards..... Nicely Done.....

"No, I understand impulses. I'm having one now!" Priceless!!

In a similar fashion, when mounting a barreled action into a stock, you should hold the stock and barreled action in a vertical position (butt down) so that the recoil lug rests against the inlet on the action side. This prevents the barreled action from moving rearward when fired and thus improves performance.

I disagree. I've experienced scope creep forward several times, never backwards. I commend you for discussing the issue, but I think you have a faulty test.

You also have scope ring caps with three screws, so what torque do u use then?

I e had this same argument so many times. You are correct sir !

Can you repeat experiment with the same torqued screws but mount it to the back to see if it moves forward?

I have been mounting scopes as a gunsmith for over 40 years I have always pushed the front ring forward back ring to back tighten to 15 inch pounds on ring caps and 25 inch pounds on base screws. My rifles have been all over the world by vehicle and plane never had a scope move

I like the left hand bolt on that gun, very nice. I only have 1 rifle with a scope and as far as I can tell its never moved.

Thank you

I agree. Its only gonna march back so far, which IMO is the tolerence btween the rail slot and the shaft that goes across the slot.

So this is a very interesting video. I’ve had two guns in my lifetime that have moved in the rings. The first was a 12 gauge shotgun where the scope slid back as you demonstrated, the second was a muzzleloader just last year that did the opposite and slid forward.

The scope on my springer air rifle moved back, then it fell apart. Now I use the iron sights.

You are right. But an exception is a piston air rifle.

Lets take a look at a scope from a while back. Unertl, used an external spring with compression against the front mount and secured with a tension adjustment ring to return the scope back forward after firing.

Thinking about it's possible that during the initial recoil the scope is moving forward, but as the rifle comes to a stops from the impact into the shoulder the scope comes to a rest rearward since that is the last force exerted on the scope. Maybe a high speed camera would be able to pickup the movement. Either way proper torque, blue loctite and carrying a torque wrench in your travel kit to validate torque setting prior to a hunt/shooting session is key. Missing a big o' buck for a $50 tool?

I just mtd one last night and considered the slop in the Pic rail for the first time and mtd it Forward, Redo tonight. Whiplash type effect?

How about mount the front ring pushed forward and back ring push backwards or vis versa, then torque the rings down extra good. Then Your covered both ways

Another way you could have explained it is how an axehead is seated onto a new handle. The furniture moves backwards when the rest of the element runs forward.

I am an engineer and the mathematical engineer and forces says the scope will move backwards. You now why? After shooting the recoil will move the stock backward, after that that the shoulder of shooter will stop the recoil and mange the stock going forward, so as the second role of Newton says the hole system of scope will moving backwards due to the shoulder forward movement of stock. Yeah thats the point gus 😅. So Mr. Tim Muss says right and the PhD guy said false. By all thing into consideration, the scope have 2 step movement. Step 1: Rightafter of shooting the scope will move forward. Step2: After blocking the recoil of the weapon, the shoulder will apply force to the butt and cause it to move forward. At this moment, the whole scope system moves back. Here, we find out that, the firmly mounting scope in place is more important than tightening the scope to the back or front of the picatinny rail. But my personal opinion is to fasten the scope to the back of the Picatinny rail as Mr. Muss said. Thanks for reading the comment 😂❤❤

I can't explain why the scope moved backwards, but there must be a reason why some rails come with a protruding tab that is to be shoved against the front of the ejection port.

Theory guides but experiment decides.

Makes sense, if the firearm recoils backwards, the scope will too. I have seen some videos by manufactures to mount the optic forwward.

the brake make a lot of difference in recoil and scope movement mount in middle and remeasure

PhD left out a negative sign in his calcs.

When I mount One it don’t march anywhere, it stays put

I've found the rear scope ring to mount to the rear against the rear rail and the front ring to the front of the rail. I've found that all but one in my life march back. So.. an ole timer showed me this way. It can't go forward or backward. Never had another issue. I agree with you but I did have one go forward for some reason over 50 years. That saying I can say this is about 4 or 5 rifles out of about 50 or so rifles. Loose screws mainly. One set of faulty rings.

Engineering states a bumblebee can't fly

Would be interesting to try the same experiment using rings with lugs removed.

I confirmed this same experiment with a "magnum" air rifle...picatinny rails. What I did was place painters blue tape at a KNOWN distance..precisely 1 mm just behind the rear scope ring on both the scope AND the barrel. (remember, there are two different assemblies here mechanically joined by tension/compression). I also place painter blue tape at a KNOWN distance, precisely 1mm just FORWARD the front scope ring and also at the scope. A "magnum" air rifle is: accelerates the pellet to supersonic speeds. Classic "crack" at muzzle is heard....typically about 1130 fps. . These higher powered air rifles even when "down rated" with heavier pellets still develop tremendous forces throughout the entire barrel breech scope mount assembly. Even when properly torqued and blue locktite, after about 100 shots, there is a noticeable creep of the scope AT MOUNT/rail AND ALSO the scope itself within the rings. The creep is more noticeable at the mount/rail attachment than the ring/scope attachment. So I then decided to start thinking about the physics involved in simple terms. It's mass and acceleration = force.. If one can reduce the WEIGHT of scope and rings and mount to rail, one can expect the FORCE to be reduced. Also thinking about physics in terms of center of moment...the longer the center of mass stands AWAY from the center of mass OF THE ENTIRE RIFLE...the higher the forces will be ...think of it as a simple LEVER. Thus, we want a scope and mount that is as close as possible to the rifle center of moment. when you put these two simple things together you have: use the lightest weight scope, rings and rail system you can install it as close as possible to the rifle. as far as preventing scope "creep" from these forces, Frankly, I do not have a good practical recommendation other than following some basic torque and thread locker advice. So have offered the idea to use BOTH forward and rear scope mount stop as two dead anchor bookends. Others have offered that instead of two separate scope rings go with a single block style where the torgue surfaces are spread out over a longer distance of the barrel. I think all of these things are worth exploring. but in my experiment this is what I found. yes, creep happens...but at a certain point, its just stops moving. It's either going to continue to creep OR it "jams" to one fixed place, shot after shot. This "jamming" effect is exactly what I found with my scoper air rifles...To INDUCE IT, I USED SMALLER WEIGHT PELLETS ON PURPOSE TO PRODUCE THE HIGHEST FORCES POSSIBLE. And after the creep stopped..about 300-500 pellets, I moved up to what the air rifles really shoots accurately (subsonic), at the higher weight pellets. I believe these shadetree "experiment" do cross over to powder rifles as the same principals remains the same. you are welcome

It's obviously due to the wrong-handed rifle.

What I do is mount the rear ring so that it is against the rear of the rail lug. And the front ring to the front of the rail lug. Torqued down to correct specs and vibratight on the screws to lock them in place. Ring caps torqued down to correct specs. And this is on my Browning X-bolt .300 wsm with no brake. It has not moved in years. ;)

I know that it moves backwards, I just wish you had a slow mow close up. Before I got a Torque driver I was cautious and did not tighten enough.

It will march backwards if your shoulder is stopping the recoil. Under free recoil it will march forward. Thanks

I personally follow the manufacturer recommendations. All of the scopes I’ve had never moved rearward. Just my experience.

.....witness marks don't lie, same as a scope that slides in rings from recoil - it moves rearward,.....just happened to my buddy a year ago,....must be from the recoil being arrested so quickly on the shoulder while in full vibration & harmonics.

I'm sorry your wrong. The scope moved back because it couldn't go forward and once the recoil impulse was transfered to your body it moved back because it couldn't go forward. Do the test in reverse and I bet it goes forward. I had a set of rings with no recoil shoulder just a dove tail and the scope almost came of the front of the rifle.

If its mounted on a picatinney its only going to move a tiny bit either way and not have any diffrence on target. Onece it seats either way give it a snug and be done

So what are the proper torque specs generally?

I have always known that it moves backward. But should we be saying that it settles back after a shot

So... If what you are saying is true. Why does an Unertl scope need to be pulled rearwards to reset for the next shot? One that is not equipped with a spring anyway. Some are, some are not. The scope slides forward during recoil.

When the scope rings are separate, then one is torqing towards the front and other towards the back of the play in picatiny chanel where it seats! But, when you torque it up to 55 in/lb you'll have no issues whatsoever!

Get precision scope rings, the recoil lug fills the pic slot, no space to get play

With loctite and proper torque scopes should stay put right?😇

Very interesting and thanks. Would be great if someone with a accelerometer could measure the forces on the scope on the initial recoil and when the recoil stops. Formula/equations are great and does solve a lot of things but until it is validate by real world experiments its just theory. Nice work.

It looks like this is a result of different coefficients of friction between the scope rings mounted on the picatinny rail and the scope itself. If it were possible to slow the footage down, we should see the picatinny rail is sliding from underneath the scope mounts as the rifle accelerates "backwards" due to recoil, suddenly decelerates to "zero" as it hits the shooter's shoulder, and then reaccelerates "forward" as the rifle itself (picatinny rail) has changed directions. Since the scope is fixed to the mounts, it moves at a different pace than the rifle (fixed picatinny rail) and we begin to see what appears to be the scope creeping backwards. A different way to explain it that what we're seeing is two objects moving at different paces due to the result of one of the objects being impacted by reduced friction. If you completely fix the mounts to the picatinny rail, the mounts do not move, the scope says stationary, all because the impact of the recoil and the resulting coefficient of friction is the same for all...the scope mounts, picatinny rails, and rifle. That's my thought!!!

The video shows what it shows, kind of hard to argue, but it sure goes against the common logic. They didn't steal me from MIT so I don't know what the PHD was trying to say but I do know the old Unertl scopes the military used had the rear of the tube free floating to allow them to move when it accelerated under recoil and the shooter and had to pull the rear objective BACK after each shot because it drifted forward under the recoil.

I always put Loctite on the screws check your your gun after a long trip that it’s on target..

A more important question when referring to supposed Precision equipment, why is there enough space for it to move at all?

sooo, no gasket seal to make sure it doesn't move at all?

you both are correct - with the firing of the rifle the scope moves forward and stays forward until the but of the rifle enconters a sholder or stop but if and when it does the scope will shift bacwards more than it did forwards because the rifle is heavier than the scope. The scope moves forwards perportionaly in relation to the mass of the scope where as it will move backwards perportionally in realtion to the mass of the rifle

Meanwhile, I just press the front ring against the rear surface of a picatinny lug, and the rear against the front face of another lug, and then properly torque the screws/bolts. Has worked thus far.

Not to start an argument - Just a comment - I have a Sharp's 45-70 w/ Montana Vintage Scope.. The scopes are meant to float - so the recoil does NOT knock the reticale loose inside. These scopes slide forward. As they are meant to move. So - before each shot - the shooter must remember to slide the scope to the reward position. Might be scope design - I'm not a PHD in anything. I did see that ur setup shows the scope moving reward.

Thank you, I had always mounted it forward, the bullet remover was a great example. I will always mount them back from now on.

Look at how the UNERTL scopes work. Real world answer.

Marches forward! ha ha ha maybe on a strong break barrel airgun. Most of my mounts have a bolt that goes across the pic rail grove that stops any rearward or forward movement like experiences on some airguns that have reverse recoil. Using a torque wrench is the best way to prevent any movement as you said.

Shooting starts at 5:30

I believe the engineer is probably a student of the same engineer that said a helicopter can fly

Also depends on the caliber… !!!

It's exactly like when you take an axe head and hit it on the bottom on the ground to make that axe head seat backwards yeah there you go okay

Simply put, under recoil the gun is accelerating backwards while the scope is momentarily stationary. Until it catches up to the rearward recoil of the gun, it wants to move forward. Mount the scope on the rail and push it that slight bit forward in the Picatinny slots before tightening.

They move backward it is a fact and I have had one do it also 👍🏻

This is the exact opposite of what I have heard and have been doing. You should move the mount forward as much as possible before tightening.

I mount 1 forward and 1 rearward . No slop , no movement .

Hell any scope will move if the mount is not torqued properly

I always mount my rings in the grooves so they are tight against the rearward of the rail groove and to see if the scope moves in the rings I have always used a minuscule lead pencil mark on the rear of the top of the scope right where it meets the top scope ring to see if it moves in the rings.....So if your scope moves the mark will also move back away from the ring.

Repeat this experiment with a .22 and 3/8” dovetail . There shouldn’t be anything for it to bounce off of. I remember when I was younger shooting a .22 a lot, the scope did walk backwards

The rail standard(s) has/have no specifications for maintaining zero. The requirement to maintain zero falls on the mount and optic side. The manufacturer sets the quality on return to zero and maintaining zero with their proprietary methods which include instructions on how the mount and optic are installed, positioned, and fixed in the rail ...

It does move back.

SEND THIS TO THE "slow motion guys" to watch in slo-mo. Maybe it'll show it bounces front to rear and or back to front !!

The scope slides backwards since the bolt is lefthand 😂 For a proper scientific test you need to test both conditions of forward and backward using the same method i.e. looser then spec mounting bolts with the scope forward and backward. To refine the test increase the bolt torque slightly and actually measure how much it moves in each situation.

All you proved is that you need to torque it down properly . Both times scope has moved on you screws were lose on your rifle so it has nothing to do with mounting forward or back

Amazing that a college educated engineer, doesn't comprehend expansion and contraction which by the way is the biggest used pattern repeatedly in creation.

Before and after shooting or traveling scope and rifle should be man handled. Scope to action . Action to stock. And back again You may not see it. But sometimes you will. feel it . Especially if groups are opening up

Spring airguns are opposite of firearms in recoil. Every free-recoiling external adjustment scope moves forward. That is why the stop is forward of the front ring. You must pull the scope rearward to the stop after every shot. Of this I am certain. Anything can happen in an experiment where screws are left loose and recoil stops are in place. Incomplete test!

The rail looks like it need s be reverse to me

Ok- so now do the same test, with inappropriate torque in screws mounted rearward- let’s see what happens…

Great demo and the use of the bullet puller will produce the opposite from the internal force going the opposite direction. That said, the body stopping the recoil is like the puller... However the pulse of the powder is far more severe as your "non-PHD" education appears correct as the body is stopping the recoil and thus a rife in motion remains in motion (used to be elementary school education stuff) until it meets another force. I started watching this recording thinking you will be wrong (sorry college educated in aeronautics no less) to realize we hopefully don't meet the opposite force, the ground in this case... Yeah your are right. using common sense and Newton's Laws, damn. I want my money back...

I always loved engineers......I read a book.....lol.....meanwhile us mechanics, living in the shit, day to day proof otherwise......like they can't comprehend.........bwaaaah.....😂😂😂...

With the rings you are using and loose it will move forward or backwards due to the no lug in the picatinny rail slot .you just proved you are not going to keep a high recoil rifle with loose rings in zero

Lol. Good video!!!

Put one ring on front and the other on the back so there is no chance it will move..

TL;DR buy a torque wrench and tighten the rings properly and evenly.

Hmmmm…. If your scope is walking backwards/forwards, it’s not securely mounted and accuracy will suffer. Your scope shouldn’t be moving at all.

I have seen this same backward movement with clamp on rings on a picatiny base. It was a new savage /scope combination mounted at factory. All mounting screws had oil which I removed and retightened with locktite. The entire scope had moved both inside the rings and the clamps back against the base notches. Now it groups sub .5 inches. All screws must be tight. This is true for any scope mounts, no matter the brand name. Thanks for the demo and your hands on experience. I think some forward movement may follow after the backward stop as a reacting force also, like a car crashing into a wall and passenger hits steering wheel and then flops back.

Problem...left hand rifle fired by a right hand shooter.

Excellent video. I am an engineer. I'm probably not very good because without any equations, my intuition was that the scope would move rearward, using a similar analogy as your bullet puller. I had gone to those other scope mounting videos that said I was wrong, so I compromised and put one ring to the front of the pic rail and one to the rear. 🤓 I have a lot of gray hair and I can't tell you how many times my calculations and expert calculations did not line up to real world. I put the equations away about 30 years ago when i figured out the guys running the machines had the answers in their shirt pocket for just about anything I wanted to know. Thanks for sharing the knowledge !

Use blue lock tight problem solved

This is like a flat earth round earth bs debate 😂😂😂

I think his engineer friend was thinking about the instance the gun fires (first impulse) but forgot that the gun travels backwards and is stopped by your shoulder. It’s this last “impulse “ that moves the scope backwards.

The scope moved back because the mounts are loose. You even stated in the begining of the video that you didnt tighten them. Maybe you should read the instrutions that came with the picatiny rail.