Why is the "54" called a scope killer?

[Jay]

 I just needed to ask our great group that question here, as mine can have a pellet sit on the RWS symbol of the reciever, just layed on a bag without being held an fired without the pellet moving? So if it has that "easy" of a recoil (it's shooting at 825fps with a .22 cal. 14.3 pellet), is it the "harmonic's" transfered to the scope, but I just can't see that as all gun's have vibration/harmonic's be it AG or PB? An it can't be the sudden start or stop(or the pellet would fall off or at least move), I have mine set up with peep's an have no intention of changing it anytime soon but I just can't get my old "powder gun crank" head around "why" it's been branded as a killer of scope's. Any insight for me?

[SAADE]

Don't know about the 54, but the 48 and 52 (48 with fancy stocks) have killed a lot of scopes.

[QVTom]

My thought is that in a regular springer you body acts as a damper and absorbs some of the recoil energy (both directions).  On a 54 the scope is attached to the action that slides freely in the stock.  No human damper so the shock to the scope may be greater with felt recoil being much lower.

Just my theory - don't own a 54 yet but is on my list.

[Mark 611]

you are correct! the energy transfer is kept with in the compression tube and the recoil of the spring has no where to go accept a little movement backwards from the sled and the vibration and shock form the spring put more vibration on the tube which transfers to the scope! I had 2 54's in .22cal and they ate 5 scopes in 2 weeks! and I couldn't find any seal problems or anything wrong with them and I was using Leapers scopes and I find them to work well on springer's so I sold both guns!

[RedFeather]

Yeah, they are only recoilless to the shooter's perspective.  Kind of like an artillery piece where the barrel recoils but the carriage remains at rest.  With 54's you need a good quality, heavy duty scope or something like a Dampa mount which will absorb the recoil.  Also, heavy duty doesn't mean a heavy scope, since the more a scope weighs, the more recoil it will be subjected to.

[Jay]

Thank's guy's. It still has me scratching my head some, guess one day if I get access to a slow motion camera I'll "see" it better or maybe I'll hook up a stress gauge like I use on PB's just so I can try an put it in perspective of there working's......Jay

[SAADE]

Jay; Paul Capello Air Gun Reporter has a video on the 54, I think it had a slow-mo of the action cycling. He's on line just google AG Reporter.

[Jay]

Thank's Brian, I never even thought of checking his vid's for a report on the 54's, and if nothing else(if I can't find the answer's there) I might even try an contact him with the question, as it still has my "powder crank" side wondering how so much vibration/harmonic's can remain to be transfered to the scope an yet a little 14.3gr pellet can still remain at rest on top of the gun?

[bobri]

Thank's Brian, I never even thought of checking his vid's for a report on the 54's, and if nothing else(if I can't find the answer's there) I might even try an contact him with the question, as it still has my "powder crank" side wondering how so much vibration/harmonic's can remain to be transfered to the scope an yet a little 14.3gr pellet can still remain at rest on top of the gun?

Thank's Brian, I never even thought of checking his vid's for a report on the 54's, and if nothing else(if I can't find the answer's there) I might even try an contact him with the question, as it still has my "powder crank" side wondering how so much vibration/harmonic's can remain to be transfered to the scope an yet a little 14.3gr pellet can still remain at rest on top of the gun?

The pellet doesn't fall off because it is free to slide above the quick backward-forward jerking motion of the receiver.  It's like that trick where somebody pulls the table clothe off a table really quick without pulling off the dishes, and actually in this example, the faster (and more forcefully) he pulls, the better chance he has of not disturbing the position of the dishes.  If the dishes were stuck to the table clothe, as the scope is to the receiver, they would all be pulled off the table with the close and break.

[QVTom]

Thank's Brian, I never even thought of checking his vid's for a report on the 54's, and if nothing else(if I can't find the answer's there) I might even try an contact him with the question, as it still has my "powder crank" side wondering how so much vibration/harmonic's can remain to be transfered to the scope an yet a little 14.3gr pellet can still remain at rest on top of the gun?

Thank's Brian, I never even thought of checking his vid's for a report on the 54's, and if nothing else(if I can't find the answer's there) I might even try an contact him with the question, as it still has my "powder crank" side wondering how so much vibration/harmonic's can remain to be transfered to the scope an yet a little 14.3gr pellet can still remain at rest on top of the gun?

The pellet doesn't fall off because it is free to slide above the quick backward-forward jerking motion of the receiver.  It's like that trick where somebody pulls the table clothe off a table really quick without pulling off the dishes, and actually in this example, the faster (and more forcefully) he pulls, the better chance he has of not disturbing the position of the dishes.  If the dishes were stuck to the table clothe, as the scope is to the receiver, they would all be pulled off the table with the close and break.

Nice analogy bobri 

[SAADE]

Jay: See bobri's comments, he hit the nail on the head or, the pellet on the scope rail in this case.

Same principle that Harley uses in (some) of their handelbar risers to keep your hands from going numb from engine harmonics. But, if you grab the bike frame or other metal to metal mounting points while the bike is running, it will shake your fillings loose.

The dense and non-harmonic lead pellet is not directly mounted to the gun, and lead is about as good or even better than rubber for harmonic isolation.

[Jay]

Thank's guy's I can see what your saying an I agree with the principle, but the pellet is set in the middle of the RWS logo ring(on round of reciever) an it does not move from it, so the slide portion of stability in motion does not completely cover it for me? LOL guess it's one of those thing's that I'll tumble over in my head for awhile. My bud on here Gary an me have sit an tried to get a handel on it when we are shooting, I'm sure it has to do with something along the line's of the "sudden" free start or stopping of the mass of the scope? Because without question they ARE known killer's of optic's so the answer is got to be right in front of me. I THANK you all for the answer's an keep them coming, it could just end up it's several factor's combined that I'm not seeing at this point.

[Nathan]

Here are two schools of thought (mine)  on the subject. I may be right or totally off base, I’m not sure.
First, this is why the M54 would be a scope killer.
 In a recoiling spring/gas ram, the recoil and vibrations of the powerplant is transferred into the stock (either wood or synthetic) because the action is directed mounted to the stock. The recoil and vibrations are partially absorbed or cancelled by the mass and or harmonic characteristics of the stock material and also by the shooters own body. Because the action (in the M54) is isolated from the stock (for the most part except by a small mounting system) by the sliding mechanism, the majority of the recoil and vibrations are transferred to the scope through the scope rail and mount(s) instead of the stock.

Why it shouldn’t kill scopes.
The Cardrew’s demonstrated in their book, “The airgun from trigger to target”, that the firing cycle of a spring piston airgun is measured (and lasts for only a few) milliseconds. I don’t recall the exact number of milliseconds. Now the sliding mechanism of the M54, while quick, takes at best hundredths or thousandths of seconds to reach the rearward limits of its travel. So (I believe) that the piston has moved to the end of the compression chamber, the pellet exited, the piston rebounded and come to a complete stop, before the sliding mechanism has stopped moving backward.  Since all the piston movement occurred whilst the action recoiled rearward, that helps to cancel the recoil and vibrations to the scope.
Again I could be totally off base. 
My M54 has not broken one scope in either stock or tuned form. I have had 3 scopes on it thus far. 2 of them were airgun rated. The 3rd I’m not sure about it. Maybe I’ve been lucky.

Nathan

[RedFeather]

Yes, the metal components of the 54 are absorbing nearly all of the recoil.  It is not recoil as in powder burners.  The piston goes forward, suddenly stops (forward recoil), the gasses combust and, along with spring contraction, hurl the piston rearward (back recoil), meanwhile the spring is scrunching up, then expanding, then scrunching not quite so much, expanding a little less, over and over, all within a few seconds.  Hence the twanggggg.

As to that stationary pellet, I have heard it performed on Whiscombes and Parks, both systems with counter or offsetting pistons.  The 54, on the other hand, is moving.  Place a marble on it and I bet it will roll, but not on the two guns I mentioned.

[AirScopes]

I think there are several ideas here that work together. The video of the shock would probably be a good diagnostic. The recoil saving in the 54 is all for the shooter. The impact of the spring and pellet recoil are all taken on by the receiver, without the benefit of weighting with the stock. Because the 'receiver on rails' does not have the bulk, jarring can be quicker -- though the impact is damped for the shooter.

I use the 54 as a test gun for breaking scopes. I use a few others too, but I think it is the roughest test. Because I like the 54 I have tried some modifications to mount a scope on the stock rather than the rail, with some limited success. That would save the shooter and the scope from the recoil.

Richard

[Jay]

 Thank's again for more insight guy's. I would have to agree that I'm going to find it "is" a combo of several factor's envolved with the 54 an it's habit of eating scope's, or like Nathan I just "lucked" out an we both have very smooth action's on our gun's? Red pretty sure a "round" object just might move LOL, I do factor in the base/area of contact of the two point's.