Scope or maybe scope mounting issues...

LongCut

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Long time follower of all things Randy, and I have been lurking around here for a while, but here goes my first post

A friend called me yesterday and is having issues getting his gun on paper:

Browing Abolt Medallion W/BOSS in 7mm mag. The rifle has worn a VX3 4.5-14 for 20+years and shot 160grn NPs extremely well. Switched the scope to a VX5HD 3-15 and 155grn Terminal Ascent. Mounted with Leupold 2 pc DD bases and rings (like he has done 100 times before), bore-sighted, then..........

Figured out he was hitting low. WAY low. Got it up to about to about a foot low at 100yds but is out of vertical adjustment. Windage was only off by about 1" from when he bore-sighted it. He called me and asked for help.

Things I learned/suggested
-Shooting "old crap ammo" to get it on paper so I told him to shoot known good ammo (He shoots Federal Premium factory ammo)
-Told him to try tuning the BOSS, but I am sure there is no data for the new ammo he has (not sure if he did this, or if it would make that big of a difference anyway)
-Checked to make sure everything was tight and hadn't moved.

He is 3 hrs away so I can't go there and help right now. He and another friend mounted an identical scope on another rifle at the same time, and it was almost spot on with the first round. So that, along with having done this quite a few times, tells me it may not be something he did???? And yes, this fell can flat out shoot, so it's not him.

I searched and couldn't find anything, so forgive me if this is a dupe...... I am waiting for pictures just in case there is something glaring that they aren't seeing. Any ideas, or has anyone run into this before?
 
Problem with 2 piece bases. Does he have the front base on the front?
And the rear on the rear?
Not sure if they are different, buttt....

Everything torqued?
Not gorilla tight, or i think it is...

Using same mounts & rings, have him put the VX3 on & try it.

BOSS system should just adjust group size, not entirely shift POI, at least to that degree.
 
I know someone who had this exact problem except he was missing to the right and ran out of windage adjustments. The dials were broke in his scope, he returned it and got a brand new one that has been in use for about 5 years now.
 
I've been dealing with some mounting issues (pretty sure there's a slight misalignment on the front base), had a smith look at it and he thought it would be okay, but when I tried to zero ran out of windage. Took the scope off the bases still in the rings and put it back on over and over again trying to figure out why it wasn't aligning, when I was about to give up I tightened it back down and bore sighted and it looked good, had it nearly zeroed within a few shots. But now I'm still having some issues getting a tight group, but I think that's due to the base misalignment.

You might try loosening the rings from the bases and resetting them and then set the scope back to zero and try again. I've read similar threads that mentioned trying that and sometimes it works.
 
std7mag - This is why I am having him send me pics. Like I said, he has done this many times before. He knows more than enough about doing this, so my first thought was defective scope. Like I said, they mounted the exact same scope with exact same bases/rings on a different rifle, and it was money from jump street.

I feel like we are missing something very basic, or the scope isn't functioning properly? I suggested taking it completely apart, centering the turrets, and starting over.

VX3 is a smaller tube so he would have to switch rings back.
 
But now I'm still having some issues getting a tight group, but I think that's due to the base misalignment.

Misaligned base will have zero effect on your group sizes.
Back to the reloading drawing board for you, i'm afraid.

Longcut,

Yeah, i'd agree. Somethings amiss.
I had recently prepped my Mauser in 284 Win for a 400 yard deer match. This included putting on a different scope the night before.
When i got to the range i bore sighted, then shot it. It was throwing shots everywhere. I ended up getting frustrated and didn't shoot the match.
Fast forward a week later. Went to put scope on my wife's rifle and found out the rings were never tightened on the base. DOH!!!
 
Misaligned base will have zero effect on your group sizes.
Back to the reloading drawing board for you, i'm afraid.
That's good to know, shooting factory ammo and haven't had a good calm day to shoot so maybe some other factors at play. My assumption was that if the misalignment was torquing the scope a bit it might affect the adjustments, like over-torquing the rings, it's a Vortex Diamondback so kinda lower end scope.
 
Sooooo,

Removed everything, recentered the reticle and remounted. Boresighted and off to the bench! He got one round on the paper, which was again, way low! Adjusted accordingly and ...... no impact/no idea. Adjusted back down to where his low hit was..... no impact/no idea.

10 rds of brand new terminal ascent at 100 yards. One round on a 12”X12” target, and not where its supposed to be.

We are both convinced this scope is not working. Again, it not the first rodeo for either of us. For a tad of reference, 3 of us are going elk hunting this fall and all 3 of us bought this same scope. All 3 used the same bases and rings (which we have in several guns), with the only difference being rifle brand and caliber. 2 out of 3 are spectacular, one is not.

Calling leupold in the am to see what they say.
 
An option, is to try the same setup on a different rifle or the same scope with different rings/bases. but as someone who works in quality never assume that because it comes from a top notch company that bad products don't slip through the doors.
 
If you have a different scope to try, with the same rings/bases, I would. And I'd suggest moving closer or a much bigger target so you can track where the rounds are going and if the adjustments are working correctly.

Usually with a new scope I like to start out with a clean piece of paper on a BIG clean piece of cardboard at 50 yards or closer.
 
This happened to me a few years ago except I was hitting high. Turns out I purchased the wrong rings for the rifle, but they were almost identical to the ones I needed. The one in the front was slightly higher than the one I needed so I ran out of vertical adjustment on my scope. I remember it being very confusing and the CSR at Midway was very confused as well. I think there was a magnum and non-magnum version of the same rings or something like that. Maybe something worth looking into. If you think it's the scope, throw another scope in there and see if that takes care of the issues. Really frustrating having scope issues because there are so many variables and it can cost alot to get it figured out. Good luck!
 
Send the scope back! Remount the old scope in original base and rings and continue on shooting the new ammo.
 
It’s not uncommon with mass produced rifles, or bases and rings. If he had to dial a lot of windage it’s possible that he actually lost most of his elevation adjustment withiut even dialing much of it. Use a 1-piece base, and shim it or get one with lots of MOA in it. The other option is Burris signature rings with off-set inserts. It’s also good to use a windage adjustable base instead of a dual dove tail.
 
It’s not uncommon with mass produced rifles, or bases and rings. If he had to dial a lot of windage it’s possible that he actually lost most of his elevation adjustment withiut even dialing much of it. Use a 1-piece base, and shim it or get one with lots of MOA in it. The other option is Burris signature rings with off-set inserts. It’s also good to use a windage adjustable base instead of a dual dove tail.
I'll disagree with that last sentence. I do want any part of my mounting system to be designed to move. YMMV...
 
I got better pictures. The setup looks good. The first picture made it look like the bases were at different heights as well as the rings. Same bases that have been on the rifle since it was born, just changed the rings due to bigger tube diameter.

I agree with shooting it at a closer distance and using a bigger target, but I am not there to do it, and someone is "doing what I always do"......... and "someone" now has it in their head that the scope is junk. I like the wrapping paper idea and will keep that in mind for further endeavors.

I called Leupold today. Started at #43 in the queue, so I left my number and per the message, would receive a call back before COB today. Less than two hours later I get a call from a Beaverton Oregon number. The very nice fella on the other end went through the whole scenario with me. I can tell he is actually taking notes. Asks a few questions on numbers, etc, then tells me he is convinced the rear base needs to be shimmed. I know our time constraints/concerns arent his issue, but no matter, he is rushing some shims out the door.

I normally can't stand calling customer service and have never had to contact Leupold, as this is the first issue we have ever encountered with their stuff, but what a pleasant experience. I hope that shims solve the problem. I will report back after attempt #3 has taken place, hopefully with a success story. That being said, I have never shimmed a base before. Sounds pretty simple, but if any of you have any pointers or tricks, I am all ears.


Mr T- Windage was off by around 1", so almost no dialing done there. That was one of the questions the tech asked. Also, I already offered him $200 for his junk scope. He politely passed......
 
I’ve never tried this, but if there’s enough clearance with your side turrets, what if you rotated the scope 90 degrees and shot another group. If the windage is way off, then it’s the scope. If elevation is still off, it’s the bases/rings? Or is that just a stupid idea?
 
I got better pictures. The setup looks good. The first picture made it look like the bases were at different heights as well as the rings. Same bases that have been on the rifle since it was born, just changed the rings due to bigger tube diameter.

I agree with shooting it at a closer distance and using a bigger target, but I am not there to do it, and someone is "doing what I always do"......... and "someone" now has it in their head that the scope is junk. I like the wrapping paper idea and will keep that in mind for further endeavors.

I called Leupold today. Started at #43 in the queue, so I left my number and per the message, would receive a call back before COB today. Less than two hours later I get a call from a Beaverton Oregon number. The very nice fella on the other end went through the whole scenario with me. I can tell he is actually taking notes. Asks a few questions on numbers, etc, then tells me he is convinced the rear base needs to be shimmed. I know our time constraints/concerns arent his issue, but no matter, he is rushing some shims out the door.

I normally can't stand calling customer service and have never had to contact Leupold, as this is the first issue we have ever encountered with their stuff, but what a pleasant experience. I hope that shims solve the problem. I will report back after attempt #3 has taken place, hopefully with a success story. That being said, I have never shimmed a base before. Sounds pretty simple, but if any of you have any pointers or tricks, I am all ears.


Mr T- Windage was off by around 1", so almost no dialing done there. That was one of the questions the tech asked. Also, I already offered him $200 for his junk scope. He politely passed......


I've never shimmed before, but I would hope they would have a slot or holes that match up with the holes on your rifle receiver.
 
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