Scope Gremlins???

[puma guy]

My brother and I went to the range to check our deer rifles earlier this week. I put a brand new Leopold VX II 4-12 X 40 AO on my Model 70 using the same rings and mounts I had for the VX II 3-9 x 40. Bore sighted with a Bushnell collimator. Checked it out at 25 yards on a 15x15 diamond target. Not even on the paper! Put a big 36" and found it was shooting about 15" high. Started adjusting and ran out of elevation adjustment. the weird thing was even though the crosshairs stopped moving I could still turn the turret adjustment. Leopold said the turret knob will still turn even though the cross hairs stop. I took a model 1710 .22LR Anschutz with a 6x24 B&L Elite to shoot at the 100 yd range and couldn't find the target with it. Took it to the 25 yd sight in bench and it was off so far right I ran out of adjustment on it. What is going on? Came home and put a 6.5-20x50 Zeiss on my Model 70. again with the same mounts and rings, bore sighted it. Reversed the rings on the Anschutz front to back and tip-off clamp on the opposite side. Collimated it and thought I was good to go. Took them both back to the range the next day. The Model 70 is drilling it with the new Zeiss on it , but the Anschutz was still impossibly off. I should mention all mounting screws were checked for tightness as well as action screws. Since the receiver on the Anschutz is drilled and tapped besides the 11mm grove decided to ordered some Redfield bases and rings for it.

Today I went to shoot my RRA Ar15 18" SS Bull barrel w/ Nikon 6-24 X 50SF that was drilling it last time I shot it, which was about a year ago. Set up on the 100 yard range and couldn't cut paper. Back to the 25 yd sight in bench. 10" high and 1" left. Moved the crosshairs to POI and put three in a quarter size group. Back to the 100 yard and it's 5" high and I run out of elevation adjustment and still shooting 4" high. At least on the Nikon the crosshairs stopped at the same time the turret knob stopped. That's when I figured there must be Scope Gremlins in my gun safes. I have no other explanation. Guess I'll be shimming the Nikon and waiting for the Redfield mounts from Midway. The ironic thing is I took a little Marlin Model 81 with a cheap silver Marlin 4x scope that came with my Model 60 and it was almost dead on at 25 yds with just bore sighting. I may go back to Bushnell Banners! I'm sending the Leopold 4-12 back to them for repair. If the Redfield Mounts don't work on the Baush and Lomb I'll be sending it to thenm for a look see, too.

[MoJo]

I just hate it when stuff like that happens

[puma guy]

I just hate it when stuff like that happens

Strangely on the second and third visits to the range I ran across two other shooters having the same issues. One was a guy I used to fish with and hadn't seen for 20 years, but he recognized me. He was shooting two rifles to check them out and both were shooting terribly even though they shot fine the last time he took them out. One was a 700 Rem 7mm Mag heavy SS fluted bbl. The other he said was a custom made rifle, but I didn't get the details. Both had high dollar scopes. The third day I watched a guy with a .300 WSM shoot at least 15 rounds at the 25 yd sight in bench after firing several at 100 yd that must have been way off like mine. He said he was having the same problems with his brand new Leopold, but finally had it 4" high at 25 yd so it should be on target at 300 yds according to him. I haven't checked out the trajectory of the .300 WSM.

Gotta be the Gremlins. BTW - I forgot say in the OP that I welcome any help and/or suggestions.

On an unrelated positive note I got a new Puma knife ball cap in the mail yesterday.

[The Annoyed Man]

I've heard it called "gone barn sour" before. I've never had to adjust a scope more than a couple of clicks in any direction once I've gotten it zeroed.

[puma guy]

I've heard it called "gone barn sour" before. I've never had to adjust a scope more than a couple of clicks in any direction once I've gotten it zeroed.

In my younger days selling sporting goods I probably mounted and bore sighted 300-400 scopes and never had a single person come back to say they couldn't get it zeroed. I'm thinking about putting a light in my safes or maybe some garlic.

[MechAg94]

They new rings and stop buying leupold?

Might retry the 4-12 on a mount with both rings on a single mount. Makes me wonder if the scope or mount has some built in elevation. Never had a scope get off that much sitting around without either getting banged up or being broken.

[MechAg94]

The only other thing I can think of is to try a scope ring alignment kit if you can get access to one.

[johncanfield]

Ammo problems? Scope mounting issues? I got very frustrated with my then new Bushmaster .308 - I was all over the target and thought the cross-hairs in the scope were jumping around so I bought a significantly better scope which did not significantly improve the situation.

After a lot of trial and error, the issues were:

Mounting rings were loosening up, used thread locker on rail bolts
I did not bias the mount to the front of the rail notches so recoil wouldn't pull the mounts aft
I was shooting different ammo expecting the same results (DOH )
Shooter error - I was not keeping the butt-stock firmly held against my shoulder
Shooter error, not keeping the Bushmaster completely immobilized (carbine length barrel of course)
Shooter error, not smooth with trigger pull
Too much wobble in the stock Bushmaster butt-stock, replaced with a Magpul

[puma guy]

Thanks to everyone for the suggestions.

They new rings and stop buying leupold?

Might retry the 4-12 on a mount with both rings on a single mount. Makes me wonder if the scope or mount has some built in elevation. Never had a scope get off that much sitting around without either getting banged up or being broken.

The rings and mount on the Model 70 are Redfield and are the same ones that I used to mount a 3-9 Leupold and have been on the rifle since 1994. I check it every year and never had to make any adjustments. I've shot deer with it every year from 60 -180 yards. It just sits in the safe waiting for deer season. I checked the screws for tightness at the range after the abominable performance.

The only other thing I can think of is to try a scope ring alignment kit if you can get access to one.

I installed a Zeiss 6.5-20 to replace the 4-12 Leupold and sent the scope back to Leupold today. I am going to hunt with the Ziess this year and maybe install the Leupold for next year. If Leupold rules out a defective scope and it still needs elevation adjustment I can shim it.
The Anschutz is just weird. Even though the rings are high quality for a groved receiver they may be for 3/8" grove instead of an 11mm grove. I'm installing a set of screw on bases and new rings as soon as I get them. If that doesn't do the trick I'll send the scope back to Bushnell which services B&L.

Ammo problems? Scope mounting issues? I got very frustrated with my then new Bushmaster .308 - I was all over the target and thought the cross-hairs in the scope were jumping around so I bought a significantly better scope which did not significantly improve the situation.

After a lot of trial and error, the issues were:

Mounting rings were loosening up, used thread locker on rail bolts
I did not bias the mount to the front of the rail notches so recoil wouldn't pull the mounts aft
I was shooting different ammo expecting the same results (DOH )
Shooter error - I was not keeping the butt-stock firmly held against my shoulder
Shooter error, not keeping the Bushmaster completely immobilized (carbine length barrel of course)
Shooter error, not smooth with trigger pull
Too much wobble in the stock Bushmaster butt-stock, replaced with a Magpul

The AR was shooting great last time I shot it and I'm using the same ammo. Mounts and rings checked for tightness. The 6-24 Nikon target scope has parallax adjustment The rifle is a varmit model with EOP and weaver style Leupold quick mounts. I am going to move the rings to different points on the rail. I am shooting a Mag-Pul PRS stock, Hogue Aluminum Free Float Tube hand guard on a Cowan bench rest with the butt stock supported by a Protektor eared sand bag. The gun is stationary and basically I can just pull the trigger once I get the adjustments made on the bench rest. I can't completely rule out the things you pointed out (all good points), but this is the same set up I shot last time. Of course I may not have compensated for the curve of the earth

EDIT: I found an old target from last August for the AR-15. About a year and a half prior to the August group I had a 5 shot group that was a clover of 4 shots w/ 1 about a bullet diameter away at 7 o'clock from the group. That was the best group I'd ever shot with the rifle. I took a picture of the August 2012 and last week's target side by side for contrast. The target to the right is from last Wednesday. 100 yd from bench rest and the same lot of Lake City 55gr ammo The first shots at the top of the target were with bullseye POA. I started adjusting down until I ran out of elevation. The group of shots above the bulls eye are those adjustment shots. Next I shot at the bottom left diamond and started adjusting for windage. I them shot at the bottom right diamond. The last shots I took can be seen above the lower vertical bar and my POA was the bottom of the bar. The windage adjustments was fine though I pulled the shot high left that's out of the string. Investigation to continue at a later date.

[puma guy]

Leopold sent the scope back and said it checked out. They did however replace the erector spring. I have not reinstalled it since I'm using the Zeiss on my deer rifle. After the season is over I'll check it with again. I also asked them about a set of turret caps to replace some my son-in-law lost and they senttwo sets for just the postage cost of $5.