Scope Shims - Ideas?

[racking up points]

Here is my issue, just placed a Mark AR Mod-1 with medium rings on my HHA to replace a previous optic. The old one worked fine, it was a VXR Patrol with medium rings. The new scope is bottomed out for elevation and I am out of left windage adjustment. At 20y I am 7" high and 7" right" and there is no more scope adjustment. To make sure it wasn't a ring problem, I rotated them 180 deg, no change in POI. So I swapped them front for back, no change in POI. So I cut some aluminum beer cans to shim the ring...3 layers later and I'm still about 4" high and still 7" right at 20y.

I went to Cabelas today to speak with a gunsmith on the issue and he seemed to know less about it than me. Told me to use paper for shims, which seemed like bad advice to me.

I guess my concern is how much shimming material is too much? I don't want to deform the main tube. Anyone with experience in this department, please chime in. Thanks

[NFH]

Have you considered swapping your rings for Burris Signature Zee rings with offset inserts?

[Boo]

Have you considered swapping your rings for Burris Signature Zee rings with offset inserts?

Yep!
You should talk to Paul if you're using an HHA.

[NEPAbowhunter]

From reading different threads on HHA problems, I believe higher scope rings are recommended to fix your problem. Surf on over to crossbow talk and do a search on HHA problems. There is some good info to be read. Good Luck.

[flightattendant100]

Dennis, (Derrick, I just had to) I know that we have pm'd about this, but I have a question. Can you put the old scope back on and see if it works as before? If so it may be a scope issue. I know its a Leupold and hard to believe, but even Leupold has a warranty dept.( the guy is a former Maytag repairman). If scope is off 7" at 20 yrds., both directions, that's 35" at a 100yrds., from max adjustment. I realize each scope can be different, and may have a different amount of internal adjustment, but 35" from max. adj. is a ton! So I'm really curious if old scope will remount and zero.
Paulaboutform had an issue at Boofest after his bow with an HHA leaned over, not even really a fall, and it shot way off afterwards ( high I think) due to a bent HHA. I'm sure curious. If old scope zeros then its not a bent HHA.

[racking up points]

Thanks for the feedback.

I have heard about the Zee rings with offset inserts but finding them in store has been impossible and they weigh 4oz a pair so that's why I was leaning toward shimming my aluminum rings.

I can't see how this could be a problem with my Optimizer scope rail being bent because the bow shot fine with the old scope, and I fired it the same day I made the swap to the second scope.

The scope was purchased used so anything is possible, right? I am trying a different Leupold scope tomorrow, if that doesn't fix the problem, it's the HHA. If it fixes the problem, it's the scope and the Leupold repairman will have some work to do...

[tremps01]

Hey Derrick, Here what i did with one of my scope.
http://www.excaliburcrossbow.com/phpBB2 ... =1&t=52616
I have a never use set Zee rings with offset inserts half of the price...........
Marcel

[racking up points]

I'll be a monkey's uncle...the problem is with the scope. Two Leupolds in 1.5-4x work just fine with plenty of adjustment, but I can't get that 3-9x40mm Mark AR on target.

It's going in for repair. Thanks for the suggestions.

[VixChix]

I had to add a couple of thicknesses of a coke can to the front of my set up. Easy peasy.

[flightattendant100]

I'll be a monkey's uncle...the problem is with the scope. Two Leupolds in 1.5-4x work just fine with plenty of adjustment, but I can't get that 3-9x40mm Mark AR on target.

It's going in for repair. Thanks for the suggestions.

Stranger things have happened.... But not many. Man, one of the nicest scopes around, don't waste your money on a lotto ticket. Glad you got it figured out.

[racking up points]

I had to add a couple of thicknesses of a coke can to the front of my set up. Easy peasy.

Thanks, Moni. Tried that and it works for elevation but not windage.

Like Paul said, 7" high and right at 20y would be equivalent to 35" high and right at 100y. I wouldn't know for certain because this is new to me, but I would think I need more correction than an offset ring or shim in my current ring could reasonably provide. And since two other scopes work and this particular one doesn't, I'm leaning toward the scope being the issue. I'm calling HHA and Leupold CS today just to make sure.

[racking up points]

I just wanted to update this. I have spent the better part of the day on the phone with CS reps at HHA and Leupold and I have learned a lot.

The problem is not related to my scope's functioning at all. I verified in a mirror that the adjustments work just fine. The stacking of tolerances, a few thousandths of an inch here and there, (for example in the dimensions of the trigger box, scope rail, HHA scope rail, rings, scope), make it so that the 3-9x40mm scope cannot zero. The big problem here is that the 3-9x40mm scope offers less adjustment than the two 1.5-4x20mm scopes I ran prior to this. In fact, the larger 3-9x40mm scope has about half of the internal adjustment than the 1.5-4x20mm scopes do. I thought, incorrectly, that a quality scope should have more adjustment, when in fact the opposite is true. The better the glass and the better made the erector system, and the more magnification, the less room there is inside the scope for adjustment.

So just shim the scope, right? Leupold says no. It is not recommended. But I tried it anyway. I put 7 layers of coke can on the bottom-right of the front ring and 5 layers at the top-left of the rear ring. It is still about 4" high and 3" right at 20y and the scope is out of left and down adjustment.

I don't think the Burris offset inserts in the Zee rings will make up for this but my next call will be to their CS department so the saga continues...

[hard2draw]

Not sure if it will help but if you are looking for some shim stock locally KBC tools have stock in a couple of materials.

[racking up points]

Not sure if it will help but if you are looking for some shim stock locally KBC tools have stock in a couple of materials.

Good to know, thanks.

[dutchhunter]

It is never a good idea to put any shims inside the scope rings ,as it can and will dent the scope tube body ,,I would look at getting a better set of rings with some built in adjustment in the base of the rings ,,,,Dutch