Scope mounting problem

[wwb]

Okay, here's the deal.... got a newer, bigger, better scope for my Savage .223, so now I have this Simmons 6-18X50 AO (which worked fine on the .223 for several years) laying around when inspiration strikes; I'm gonna put it on my target 10/22.

So I remove the 4-12X40 AO that was on the rifle, and set the new scope in the lower half of the rings.... just as I figured, I need taller rings. Call the good folks at Midway, and a set of Extra High Grand Slam rings is on the way.

Check the mail yesterday, and "oh boy! oh boy! oh boy! they're here" Mount the scope, run out to the range, and check it at 25 yards. WTF ???? I run out of elevation adjustment and it's still shooting low and not zeroed. Is it possible that there is one ring slightly taller than the other? No dial caliper along, but I have the tools handy to simply swap the rings front-to-rear.... if there's a difference, that should make it shoot high, and I can bring the elevation back down.

No dice... still shoots low with the adjustment bottomed out. Could it be the base? Nope... it's tight. The barrel?... tight to the receiver. The old scope zeroed with minimal adjustment, as did this scope when it was on the .223.

Color me puzzled.

 

[golferboy426]

sounds to me like your scope is upside down

 

[Richbaker]

Shim the front ring, between the bottom ring and tube... Or, shim the front end of the base.

 

[wwb]

Shim the front ring, between the bottom ring and tube... Or, shim the front end of the base.

Backwards... it's shooting low, so I'd need to shim the rear. Shims under the base are the lesser of two evils... shimming one ring makes the tube pass through the other ring at an angle... a tiny bit is okay, but more than about .010" will dimple the tube at the other ring.

Just wondering if there's something simple I overlooked here.

 

[Richbaker]

Yep.... Minor brain fart.

 

[Mobuck]

The rings with the eccentric polymer inserts are a better solution. Truthfully, I can't see any reason to put that scope on that rifle but it's your choice. I had a couple of 10/22 related issues that required the insert rings. Both involved shooting too low to be adjusted.

 

[wwb]

The Burris Signature Zee rings with the eccentric inserts would be ideal, but they are not made in "extra high" configuration (as I finally found out after trying every place I could think of). So, I ended up shimming the base.... punched a hole in each piece to index it on the forward of the two rear mounting screws, and cut 4 pieces of .0075 shim stock, increasing the length of each piece so that when stacked, they formed sort of a stepped ramp. It now zeros at 100 yards with the elevation adjustment reasonably close to center.

Mobuck .... this particular 10/22 has an aftermarket bull barrel, trigger, and stock.... the barrel has been set back, rechambered, and matched to the boltface by CPC. Take my word for it.... this scope is perfectly appropriate for this rifle's performance and intended purpose (small critters out to 150 yards).

 

[golferboy426]

I'm waiting to see what caused this. It sounded so unusual