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Can you share with me your shimming a scope nightmares?

Posted: Mon Dec 24, 2007 10:15 pm
by RedNeckIndian
I got my son a new scope Bushnell 6x-18x/40 mm, AO for Christmas and mounted it on his Ruger 77/22. We've alread shot it. Dang it anyway, its shooting 2 1/2 inches low at 25 yards with the dial maxed out. What the heck. I have been mounting scopes for years. I have never had a scope maxed at 2 1/2 low at 25 yards.

Can ya'll tell me a little about your shimming projects and can I raise my cross hairs 5 or 6 inches by simply shimming?

Thanks much,

RedNeckIndian

Posted: Sat Jan 19, 2008 7:32 am
by mike4764
There is something wrong there, either with the scope or the mount. I would first check the scope. Put the rifle in a stong mount and look through the scope at a fixed position. Turn the dials up and down and see if they move all the way, sometimes the erector gets stuck and will not move. If so send it back or buy another one. Another problem with the 77/22 is that some of them will shoot very low do to the v-block pulling the barrel down. Do a google search on 77/22's and you should find a new v-block to correct that problem.

Posted: Sat Jan 19, 2008 7:39 am
by Bob259
Also check to see that your Ruger mounts are seated all the way properly and of the same height. I have never seen one that far off unless the mounts are incorrect.

Posted: Sat Jan 19, 2008 10:00 am
by NewAZShooter
I had the same problem with my 10-22 until I flipflopped the rings and shimmed one of them. Removing and reinstalling the rings turned 180 degrees so they tighten onto the base from the other side of the rifle got me on the paper. Don't ask me why. Someone at the range suggested I try it, so I did. Then I cut a bit of a soda can I found at the range to use for a shim (of double coke can thickness) and that got me the rest of the way on. This might make the seasoned shooters grimace a bit; but hey, any port in a storm. I have not had any problems with it since I did that.

Actually, I think it might have been a Dr Pepper can. So Edgehit (who so infamously used the same to fix an ejection issue) is not alone. For starters, shoot what you have. Find a way to make it work and go have fun shooting silhouette, that's what I say.

Good luck with your Ruger. I still like my 10/22 and M77 Varmint. Once you do some trigger work on 'em they come into their own even if they are not the "best" rifles available for the sport.

Posted: Sat Jan 19, 2008 10:34 am
by Irish764
I can second the coke can shimming technique. I built two Ruger 10/22's. One with a Whistle Pig Barrel and one with a Majestic Arms barrel. The Majestic is the one that required the shimming but I've had no issues since.

Posted: Sat Jan 19, 2008 11:51 am
by pistolero45
I have some .004 inch shim stock we used to use repairing F-4 Phantoms. PM me your address and I'll send you a piece.

Posted: Sat Jan 19, 2008 12:52 pm
by sobrbiker883
Flip the mounts would be my staerting point....
Have you recently free floated the barrel, as the Ruger barrel mounting has a tendency to droop? If no, you may try a pressure pad under the barrel (I prefer free floating barrels, but some rimfire afficianados like pressure pads........).

Or, Burris Signature Zee rings with the offset inserts would be the best fix if the scope functions properly and the rifle shoots well.

Posted: Sat Jan 19, 2008 1:13 pm
by _Shorty
B-Square Interlock adjustable rings are another good alternative. Got their #10101 rings on my CZ 453 Varmint. I believe they also make 3/8" dovetail versions, but mine in particular are 11mm versions. They're adjustable for height and windage, and they tilt so the angle from one being higher than the other won't matter. No damaged scope tubes.

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Posted: Sat Jan 19, 2008 2:58 pm
by chickenchoker
Where did you get those B-Square rings? Do they make one for a centerfire? Looks intresting.

Posted: Sat Jan 19, 2008 3:16 pm
by GTKF
I got them from Pyramid Air (DAGS). Use them on a standard gun where I als had a shimming problem. They work great. I believe Midway als has them.

Ken

Posted: Sat Jan 19, 2008 11:19 pm
by _Shorty
http://www.b-square.com/ is their page, and they have a catalog for download there too. I think their "standard dovetail" rings are what fit standard centerfire "weaver" bases. The #10201 rings are for 1" tubes and the #10230 rings are for 30mm tubes. Looks like the adjustable ones don't come in a 3/8" dovetail version after all. But the 11mm version fit my old Savage's 3/8" dovetail ok. Wasn't a perfect fit, but they held and didn't move. Fits the CZ's 11mm dovetail perfectly, though.

SCOPE MAX OUT

Posted: Sun Jan 20, 2008 10:12 pm
by Evelio Mc Donald
REDNECK
First of all those scopes are not build to shoot at 25yds.
Like somebody else suggested, you need to shim the back ring. I found that a piece of a water plastic bottle will do the trick, it is already curved, about the right thickness, and it will not compress under torque. Once is shimmed go to about 60 to 75 yds. and sight it in, that should put you about half way in the elevation adjustment.
It should give you enough adjustment to get down to 25yds. and more than enough to get up to 100 YDS.
I hate to say this, but I run into some 77/22 that the dovetail were not machined properly ( miss aligned ) the receiver is extremely hard, and a pain in the a__ to re-machine.
Evelio.

Posted: Wed Jan 23, 2008 8:07 pm
by Jerry G
Ttwo thickness of an alum can under the back mount has worked on all my guns. Don't tighten the screws too tight and crush your scope. Use a little common sense on that.

Posted: Wed Jan 23, 2008 8:09 pm
by Jerry G
Somewhere near my SB turkey setting is what I use for the 50 ft indoor range.