Scopes that won't hold zero ?

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fishinwrench

fishinwrench

Member
Nov 25, 2017
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mo
Surely someone has opened up a few scopes and can tell me what some typical issues are.
I have 3 different scopes from 3 different manufacturers and all 3 have the same issue. They'll shoot fine for awhile then for no apparent reason the POI shifts and they'll require adjustments, then they'll shoot good for awhile again.....then do it again.
The one pattern that always seems to be consistent is that when they shift it is ALWAYS low and to the right. NEVER EVER is it HIGH or LEFT.
I suspect that the spring is shifting, but these, while not "top of the line" scopes, they aren't exactly cheap cheesy scopes either. Don't they fix the spring(s) so that they will hold their position? Doesn't seem like too hard of a problem to solve if that's the case.
I can't imagine what else inside the scope keeps moving around. And how the hell can it always be in the same direction? If I just keep adjusting in that direction.... enough times, will it eventually stop and hold?
It's freaking crazy. I wanna tear into one and see WTH is going on.
Could it be a lens spinning, or shifting?
 
Have you determined that the scopes are the problem? Do you have a different gun, different rings to check to see if the scopes act the same when on a different gun? I suspect that it's something else besides the scope. Also check to make sure your barrel is secure, the last time I had a similar problem with shifting POI I had two things going on, I had a loose breech screw and loose barrel.
 
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What kind of gun is the problem scope mounted on?

As I understand, the common scope has a free floating design where the adjustment is made the sight itself is not captive , rather it rests against the adjuster mechanism. A hard shock can separate the sight from the adjuster allowing for "drift".

It is early and I am wrong at least twice a day, so take it with a grain of salt.
 
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On a Diana RWS 34, but the scopes (2 of them) did the same thing on my Gamo Swarm. One of the scopes I am dismissing as just being a POS..... but the other 2 shouldn't be. Take the scope(s) off and the iron sights are still zero'ed so it's definitely the scopes.
i mounted one on my shop vise and put a piece of tape on the wall. I can peck and tap on it all day long and the crosshairs stay put, but put the darn thing on a gun and it won't hold zero but for 50 shots MAYBE.
The scope or mounts are not moving, I made pencil marks on everything so I could detect any movement, never a budge.
Something inside the scopes are moving around. Could it be a lens rotating around or shifting back and forth and causing a parallax type thing ?

When they lose zero it is always low and a bit left. Every time so far.
 
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One of these is a 69.00 Hammer3-9x40
I am real close to ordering a UTG Leapers 
3-9x32AO but I'm afraid it will just do the same crap.
I just wish I knew what was moving around in there. No rattling or anything but there is some "wiggle" in both turrets. Just a little bit. Pretty sure that's just the way it's made though. I can't justify a 300.00 scope.
 
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"Redtide"It may be worth your time to take a look at Bushnell Trophy scopes. I used a 4-12x40mm on a R9, TX200, Pro Elite and Crow Magnum and never had an issue.
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Depending on their eye relief they might be too long for the Swarm. The 10x magazine system on those guns kinda limits your choice of scopes.....or so it appears. I know that 12.6" is too long unless the eye relief is very short. 12.2" -12.4" is fine.
 
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"P.O.I."You may be having the rings riding back on the rail also. mark the ring positions on the reciever with tape and confirm the ar not creeping on you.
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Appreciate the reply. I made some pencil marks and can detect no movement between rings and base, or rings and scope. I've wasted 3 tins of pellets trying to figure this crap out and I'm sick of it.
I'm just going to order a Bushnell AR/223 and see how it goes. The reviews on that scope are fantastic. So....Fingers crossed.
 
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"Windmill01"Fishinwench lets us know how that scope goes please, Ive been thinking of buying one also.
Gary
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Well I found one at Dick's and overpaid by about 35.00 over what I could have bought one for online, but I was anxious to have my hands on one. Turned out that I need new rings though....and had to order them, so I should have just waited.
The scope is pretty freakin sweet ! Came perfectly optically centered and turrets zero'ed at that position. It tracks perfectly and smacking it pretty hard on the palm of my hand doesn't cause anything to move around.

It's a heavy sumbitch (if pressed for a negative comment, that would be it) but I have confidence that it will do quite well for me. Seems sturdy. Only time will tell.
 
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