Scope shim question.

[mlrs_27m]

I have a cometa fusion .177 that will not cooperate with scopes. The first two scopes I mounted could not adjust far enough to the left. The scopes were a center point 4x16 40 and a bsa 4x12 44. The third is a new center point 4x16 40. This one would not adjust high enough.
 I placed a shim in the rear scope mount. It worked perfectly. The scope now shoots where I want it. My concern is the uneven pressure on the scope. I am worried about the scope being damaged from the edges of the mounts. I used a thin piece of cardboard for the shim. Any one else shim their scope mounts?

[Orin]

I shim all my scopes for windage after optically centering them, and to compensate for very mild barrel droop, but you have to be careful not to shim too much.  Ideally, you would want your scope optically centered on whatever zero you pick to give you the fullest range of adjustability.

Here's my rule of thumb, since all mounts are not created equal:  Lay your scope in the mount with the top rings removed.  Try to slide a shim between the scope and the mount.  If it doesn't slide in without force, it's probably too much shim for the setup and you could risk damaging the scope.

If you're completely outside the adjustable range of the scope, shimming probably won't help much.  Even if it does, you'll still be near the edge of the adjustment range and you might wind up in the same situation again if you decide to change your zero.  The best solution would be to get an interlock adjustable mount like one of these:
http://www.pyramydair.com/s/a/B_Square_10101_1_Interlock_Adjustable_Rings_11mm_Dovetail/235
http://www.pyramydair.com/s/a/B_Square_17501_Interlock_Adjustable_AA_1_Pc_Mount_w_1_Rings_13mm_Dovetail_Fits_BSA_Rifles/253

- Orin

[djmyers]

I shimmer one with a peice of electrical tape and the other was shimmer when I got the combo from pyramid air. Both are fine and have had hundreds of rounds put through them. I think as long as you don't go nots with the shims you will be fine.

[daveshoot]

I have only had to shim a couple, and used 35mm film negatives (remember those?). I read about it somewhere, and it worked out well. On one a single thickness did it, on another it took two.

I have also used this to raise rear sights on a couple of pistols that have insufficient range of adjustment.

[HNT5]

With my Crosman quest. Shot impacts were way right at 10 yards. I knew I would run out of adjustment on the scope. I was using a 4X32 AO scope in a 1 pc mount. When I held the gun up and looked over the top I could see that the scope grooves cut into the receiver were off from the barrel. Imagine the scope pointing at the 12 o'clock and the barrel at 1 o"clock. It was noticeable to the eye. I didn't have a adjustable mount to use and I didn't want to spend $50 for a mount on a $90 rifle. So I clamped the barrel (with padding of course) in my vise and pulled on the stock. Took a couple of tries, pull, go shoot in the basement, not far enough, go bend some more etc etc. But I got it pretty close, then picked up the rest of the adjustment with the scopes internal movement. If you're careful it can be done.Just another option to consider.

Nathan

[michael90t]

yup I agree with nathan... both B3's I have worked on recently had "reverse" droop meaning the barrels where angled up! lol had the uh..... finesse bothof them to get them into range..... heck mine was much worse then my boys as at 10 yardsit was shooting 2-3inches low and at 15 it was 4-5 high!!!!!!!!! and thats after bending it once because you could take a streight edge on the reciever and it would be hitting the barrel 3/4 of the way down it!!!

[thebookdoc]

I wouldn't shim the scope. I like Orin's solution, but I use a much less expensive one on my Cometas. Here are some pictures of the mount I suggested. I've got a shot here of a 40mm and 50mm objective. The 50mm leaves maybe 1/8th of an inch. I can get you the whole setup for under $40 (PM me) and it is tremendously flexible. Better than mounts I have bought for $100 and more.

[LongIslandArcher]

That scope looks like it's mounted too far back.  Are you getting enough eye relief?

[thebookdoc]

It is perfect for me. I find my cheek generally rests near the rear of and cheek rest when holding a gun comfortably. Until I started using this mount, I had to crane my head forward a bit unnaturally, and I think it led to some inconsistency in how I was both holding guns and how I looked through sights and scopes. Everyone may not like it that far back...and I'm not trying to float any agenda...But I'd rather make the rifle fit me than the other way around.

[daveshoot]

That is a pretty slick mount. I'm sure it works regardless of how far back the scope is positioned (because that would be too far back for me). What do you call that thing?

[popadave]

Neat Mount! Who makes it? What is it's model number?

Re shims: I have used small strips cut from soda pop cans. Usually one is enough.

[thebookdoc]

The mount is from Hawke. I am a Hawke dealer, you can PM me if interested...I make almost nothing on the reselling of these with costs for shipping, but I think it is a great solution -- and I was looking around and invested in various mounts. I charge the least Hawke allows, and $4 flat shipping. The extended version (pictured on the rifle) is just under $40. The shorter version is actually more ($46). So it is adjustable, flexible, and with some of the heftiest screws I've seen on a mount (2 on each side) it goes nowhere. I've tried every adjustable mount I can find and this was both best and cheapest. This same thing from b-square (same EXACT thing) is twice as much.

[LongIslandArcher]

Ah.  I only mentioned that because I guy I know shot my RWS 350 Magnum and the scope came back and bit him in the eyebrow and caused a cut that bled profusely.  Eye relief on the scope I have on the 350 is about 3" and he stuck his head too far forward (he never shot a rifle before), and before I could stop him, he had already pulled the trigger.  When I shoot my deer rifles, I lean forward into it with the stock solidly welded to my shoulder and cheek, so I never let the recoil of my 7mm Rem. Mag. cut me with the scope or push me back and off-balance.  I guess I carried that over to shooting my air rifles because I can practice with my air rifles without changing the way I stand or hold and of my rifles.

[Orin]

That's a very tempting setup.  Does it adjust for windage, by any chance, or does Hawke have something similar that does?  I tend to mount my scopes further forward than most people, and this looks like a great solution.

- Orin

[Orin]

I like that idea.  Aluminum won't squish over time, compromising the zero (like paper or electrical tape tends to), but is still soft enough not to damage the scope.  Also a fairly consistent thickness.

- Orin