Crushed scope tube

Forums Optics, Scopes, Rings, & Mounts Crushed scope tube

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    ptthere
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    I swapped a scope out the other day and noticed something. It seems that I crushed the tube on my Discovery VT-R (on both ends under the previous rings). Apparently I need to invest in a good torque-driver.

    Interestingly, the parallax and magnification adjustments all still work like new. Nothing internally has seemed effected. Granted, this particular scope is built like a tank, but I was surprised nonetheless. Side-note: This is not an advertisement for Discovery.

    From a glance you can't really tell anyway… That, and I put bigger rings over the tube, so as long as it works I guess. Still up in the air on it though.

    PT

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    bubblerboy64
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    The only way I see that happening is if the ring bases are misaligned in some manor.  What I am saying is if you put the rings on the scope unattached to a rifle you would strip the heads off the screws before you would crush the scope tube.  It’s something other then just over tightening.  

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    Quagmire
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    I did that once several years ago. It was a cheaper Simmons scope that I had been given and was mounting it on one of my .22 mag hunting rifles. Luckily I didn't destroy the scope. I did purchase a Wheeler FAT wrench shortly after. Haven't repeated the same mistake since.

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    lethemgo
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    I've seen this happen to a couple of scopes and that makes me extremely careful installing them. I try to go in small tightening increments keeping the gaps equal on both sides of the ring. The way I have on over tightening stuff guess I've been lucky so far. 

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    JamesD.
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    Use gap feeler gauges to keep the pressure equal. Rings only need inch pounds not foot. 

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    ptthere
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    I have paid close attention to the gaps while tightening. I focus on a plumb-line while everything is level and carefully work my way around. I think my biggest mistakes were not using a torque wrench/driver, and using a long-shank hex key which probably provided more leverage than I needed. But, like I said the scope seems to be fine so far, I am just surprised that I squished it. I see an in/ft torque wrench in my future lol.

    PT

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    bubblerboy64
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    If you look at the scope tube I’ll bet you it’s indented in one area around it’s circumference more then others indicating base misalignment.  I Just don’t think you could damage the scope otherwise unless you used extreme force.   The other test would be to use a straight edge and see if the tube is bent as well as crushed.  I’ll bet it is. Doesn’t take much to damage a scope if you overtighen and it’s not sitting straight on the base which is why shimming scopes is a BAD idea 

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    Quagmire
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    Most scope manufacturers will recommend no more than 20 inch pounds of torque on the ring screws. I tested a few junk scopes I came across. All of them showed signs of deforming at 25 inch pounds. These were all one inch tubes. 30mm tubes may take a bit more, but there's no reason to find out.  

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    RogerV53
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    I've seen this happen on several not all cheap scopes, soft tube material. I have a tendency to over tighten rings especially on spring guns and have learned not to buy scopes with soft tube material the hard way. Even if you align everything properly over torquing will crush soft tubes faster than harder ones. I have a old Bushnell  Banner 6-24 that's been crushed so many times it needs tape warped around it to tighten it, but it still works great.

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    Bigragu
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    The rings probably needed to be lapped. I make it a rule if using inexpensive scope rings they get lapped no question. Expensive rings I check them with a scope ring concentric tool first. The only rings I don’t bother even pulling out my scope mount tools on are one piece DNZ mounts, which I have on all my centerfire rifles.

     

     

     

    These are the FX no limit rings I just installed last week. The concentric tools prove no lapping is required. These rings fall under the “expensive rings” category. 

     

    And, yes, as suggested by others, a torque wrench to set the screws should be in your arsenal as the finishing touch to scope mounting.

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    ptthere
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    Thanks for the replies.

    Yes indeed, I definitely need my own personal in/lb torque driver. I was a bit surprised about it considering I haven't ran into this before and I didn't feel like I had wrenched on the screws "too agressively" with the previous rings. But after inspection I have noticed that the previous mount/rings was definitely machined out-of-round and not concentric.

    PT

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    Bigragu
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    There’s a Leupold chart out somewhere, as I used to have it, that told of proper torque values for certain type scope ring screws and ring mount bolts/screws. Not saying I’m correct, but most I go on any scope ring screw is 18 lbs inch and 22-25 lbs inch on mount bolts to scope rail. Locktite or vibratite on the scope ring screws only, none on the ring bolts that attach to the scope rail since I tend to remove the scope when performing maintenance on the rifle.

    Now, for break barrel gas rams and spring piston rifles, same torque values, same lock tite procedures, but I always smear a dab of rosin paste on the inside of the rings to assure that the scope will not budge forward or back. I found rosin paste at the local sporting goods Big5. Look in the baseball section. There’s a tube of it in bar form, that batters rub on their batting gloves and bat handle for grippage. I just use my fingernail and scrape off a tad bit to wipe onto the rings. 

    When working on cars and you have to thread on a tiny nut onto a bolt that is in tight quarters, I often dab that rosin on my finger tip so the nut wont fall into the engine compartment, lol, and I can thread it on by fingertips.

    • This reply was modified 1 year ago by Bigragu.
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    bandg
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    Sounds like you need to get yourself a big ol' murican car with an engine bay like a warehouse.😁

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