Explain to me how a cheap scope looses zero if...

[rdhj]

you are in the middle of the adjustment range so loosening tension on the spring shouldnt be the cause?  What other issues can make the scope not hold zero...Thinking the centerpoint that came with my nitro venom is having issues...i check where it was in the adjustment range and it was in the middle.....

[Bentong]

Have you tried optical centering your scope? If you don't optically center your scope you might max it out and still not zero it in. If you get lucky but it's touching the tube..it will wander as you shoot it. You can also mark the tube of the scope to your ring and see if it slides, same thing with the scope ring to the AG action. Try here for optical centering > https://www.pyramydair.com/blog/2005/07/how-to-optically-center-a-scope/

[Booger]

It is my opinion it is hard to make a quality product with cheap materials. I do have 2 CP scopes and expect them to die any day, because I got what I paid for. When I sell a couple more guns I see some nice scopes in my future.

[Roadworthy]

Are you sure it is the scope and not the gun?  My first Nitro Venom would zero and hold, working for a period of time - then mysteriously change POI up or down - the gun's choice.  It turned out not to be the scope.  The culprit was the piston seal.  I replaced it with a Maccari and lived happily ever after.  So yes, it COULD be the scope but it is not necessarily the scope.

[rdhj]

Are you sure it is the scope and not the gun?  My first Nitro Venom would zero and hold, working for a period of time - then mysteriously change POI up or down - the gun's choice.  It turned out not to be the scope.  The culprit was the piston seal.  I replaced it with a Maccari and lived happily ever after.  So yes, it COULD be the scope but it is not necessarily the scope.

i had already replaced the  piston seal and  cleaned it all up and applied molypaste.....had it shooting good last week and then yesterday it was about 3-4 inches low at 20 yards for some reason

[rdhj]

i was thinking..would changing the position of the objective lens affect the zero.....i was thinking it shouldnt as that is what you would be doing if you had an AO scope with the adjustment on the front of the scope.  Am I missing something here.    The is the only thing I changed.

[condor22]

 Can't say I understand optically centering the rifle scope after being Zeroed first?  optic centered, now re zero, would it not be exactly where you started at 'ZerO' before (optically) centering?    Makes sense to center scope before aligning scope rings with elevation and windage adjustment. 

IMHO The best way to check a questionable scope is to replace it with a KNOWN good scope. Put the KNOWN good scope on the rifle and shoot some groups. Good groups, other scope is bad, bad groups with KNOWN good scope, scope mounts or rail or rifle have issue's. 

[condor22]

i was thinking..would changing the position of the objective lens affect the zero.....i was thinking it shouldn't as that is what you would be doing if you had an AO scope with the adjustment on the front of the scope.  Am I missing something here.    The is the only thing I changed.

 On a high quality rifle scope, setting the parallax, will enhance your accuracy! On a low quality rifle scope, changing parallax may or  may not change zero/Poi. I have read post stating that a change of the parallax did change zero/Poi.   You may want to set the scope up exactly how it was set when you zeroed and test again.  Most scope manufacturers recommend always turning the parallax adjustment in the same direction. As in if you go past focus, back up past that point and turn the parallax adjustment the same direction again to the focus point.