Scope Shifted Zero

[Mule3006Elk]

I can't for the life of me figure out what happened. Zeroed the rifle before hunting season. No adjustments were needed. I torque actions screws, base clamps, rings ect., every year. I shoot my deer no issue with said rifle. A few days later my son who has never missed a shot cleaned missed a deer from 235 yards, prone, minimal wind, very steady rest. We watched the deer for 10 minutes, walking normally, no blood, and then started feeding again. Acting 100% normal. Checked the area NO blood. I have no suspicion this deer was hit. He commented that the shot felt great. Head scratcher. No one is perfect but my son has harvested 7 big game animals and never missed a shot or wounded an animal. So I'm thinking human error or the system (gun, scope, rings). Range Finder is working perfect. I use a Kestrel for dope and have done velocity verification. Not that I needed one at 235 yards.

I shoot the rifle and POI has shifted 2" to the right. No elevation change. WTF. We carry this carry on the shoulder or on the bag. Rechecked all torque settings > no concerns.

I did some additional range work. I adjusted 8 clicks to the left. Now shooting 1" in the right. Something is wrong. Then I did a full 6" to the left and 6" up. POI within expected POA. Shifted 12" to the right and 6" down. POI within expected POA. Returned to zero and shot the exact same hole.

I dropped the rifle 18" on the right > shot, dropped on the left > shot, dropped on the turrets > shot. Same protocol from 36". No significant POI shifts identified.

This is a Vortex PST (I know) 4-16x50. 9 years old but never had any issues prior to this. I switched out the scope.

Any thoughts what happened besides it's a Vortex?

 

[Q_Sertorius]

Being off by 2” to the right at 100 yards doesn’t explain completely missing a deer at 235 yards.

How large are the groups you fired to confirm that it was off zero?

Did you check for cracked rings?

 

[displacedtexan]

Being off by 2” to the right at 100 yards doesn’t explain completely missing a deer at 235 yards.

How large are the groups you fired to confirm that it was off zero?

Did you check for cracked rings?

Treed me.

My exact first three thoughts.

 

[Mule3006Elk]

Being off by 2” to the right at 100 yards doesn’t explain completely missing a deer at 235 yards.

How large are the groups you fired to confirm that it was off zero?

Did you check for cracked rings?

Agree. Base on angle. POA frontal aspect front leg. All variable, not a perfect shot more than possible, angle, POA, it could in this case. But more interested in the scope aspect.

3/4" group 5 shots.

No indication of compromised rail (badger), precision matched rings (vortex). I pulled the scope and checked the rail torque > looks good.

This scope, prior to this, was solid. Tracked well ect. Never dropped or abused. Not getting beat on a quad gun rack. Things fail. I may not get an answer without someone looking at the internals.

Thanks for the input. Experience is gained sometimes by failures. Want to make sure there's not something I'm overlooking.

 

[ResearchinStuff]

Double check the ring clamps onto the rail, those can crack but you'd normally see it with a drop test poi change

 

[Mule3006Elk]

Double check the ring clamps onto the rail, those can crack but you'd normally see it with a drop test poi change

I should have mentioned that. Clamps and clamp screw torque look good as well.

 

[Kyguy]

How many rounds on the scope? Just curious. People don't want to believe it, but anything can fail at any time for any reason. I don't care what the brand is.

Agree with others, 2" isn't going to make a difference at 200 yds in that situation. He pulled the shot, plain and simple.

Does the rifle have a brake or can on it? Did you check to make sure they're still tight?

 

[grfox92]

I think what happened was Vortex.

Sent from my SM-S931U using Tapatalk

 

[Mule3006Elk]

How many rounds on the scope? Just curious. People don't want to believe it, but anything can fail at any time for any reason. I don't care what the brand is.

Agree with others, 2" isn't going to make a difference at 200 yds in that situation. He pulled the shot, plain and simple.

Does the rifle have a brake or can on it? Did you check to make sure they're still tight?

probably close to a 1000 rounds. No break or can.

 

[Kyguy]

I say put it back on the rifle and beat the snot out of it and see how it acts. Heck it might go another 9 years and be fine. Who knows.