Home Forums Hunting & Shooting Hunting Rifles HELP! shooting high,scope bottomed out

I'm new to these forums,but I know there is some wisdom here.I have win 70 22-250, heavy bbl, high rings, 6x burris sig. scope My scope is bottomed out and I'm still high 4" @ 25 yds. Do i need to shim low rings up to clear scope,or shimhigh rings to cuase front to drop or ??? If anyone has faced this before please let me know

If your rifle is shooting high, you need to get the scope pointed up to be more in line with the bore. This can be accomplished with a shim under the scope on the front ring, or else with Burris Signature rings with an eccentric insert.



As a rule of thumb, each 1 thou shim (0.001") will move the point of impact 1" at 100 yards. At a minimum, you will need upwards of 20 thou to get centered at 100 yards. I would suggest that you back the scope adjustments off from the extreme of the adjustment, back some toward the centre of the adjustment range. This can cause some parallax problems.



For shims, try plastic ice cream or yogourt containers. Stable and work well. Use a set of calipers to find a shim in the thickness range you need.



You can also use aluminium shims under the front scope base. The sides of soda or beer cans work fine, you will probably need slightly longer scope base screws to get this tight. Either method will work.



Just be careful when you tighten the scope rings if the shim is installed between the scope ring and scope, that you don't dent the scope tube, there's a lot of pressure on the tube when this is done.



Realize that either way you are stressing the scope tube as the rings are no longer parallel and in line with the scope tube body. The Burris offset ring inserts are probably a better answer, but of course means investing in new rings and the eccentric insert costs a bit extra as well. Hope this helps.

I have run into this problem more often than not when mounting scopes. As Rick mentioned, there are different ways of approaching this, but I would just go ahead and make the investment in Burris Signature rings and the offset inserts. Among the reasons I recommend this is because it is possible to damage your scope when you move things around with base shims, unless you really know what you are doing in terms of "advanced" techniques such as aligning and lapping. The Burris inserts are made of a synthetic material and they rotate like a kind of ball and socket to self-align. The plastic is real tough and really grips the scope without denting it or making those nasty ring marks. It's pretty hard to screw up your scope with them. You didn't mention what brand of bases you are using, but Burris makes the Signature rings to fit a variety of bases. They are a bit tricky to set up, but they can be used to center the scope around the clock, not just straight up vertical or horizontal. I believe that Burris recommends a maximum of about .030" offset, which can be accomplished with a +.020 shim in back and a -.010 in front, assuming that more elevation is what you need. Good luck!

Paul

I just re-read your post. You said you need less elevation, not more, so just reverse what I told you about front and rear shims. Rick told you right.

Paul

you guys have been great,thanks for your help,and time

hilltopper
Why you using high rings?
Won't medium give you slight clearance between the bell and your barrel?
Just asking.
As Jim mentioned an aluminum pepsi can is near .004, and is easily cut with a pair of shop scissors.
I would shim it under the front base. Something about putting anything between the tube and the ring makes me say no-no, that might cause damage to your scope.
Don't forget to lock tight the base screws after you get everything set the way you like.

I'm with BigWad, use the lowest rings that will work. I ordered a set of custom rings for a rifle that where excellent quality. But they where about a foot high at 25 yards. Not good. If I wanted a 2000 yard gun they might have worked?

Agreed that you really should go to the Burris eccentric rings. If you don't, you'll also need to lap in your rings, otherwise you risk severely tweaking your scope with rings that are on two different planes.

Yet another alternative, is to bed your scope into your rings, with about .020 space between the scope and metal surface of the front ring. A cheap way to go $$ wise, but will take an investment of your time. This is also a very secure way to do it.

Perhaps most importantly, you should find out WHY are you 4" high at 25 yards ? Poorly machined reciever? Poorly machined bases? Bent scope? Barrel bent? Wrong bases for your application?

Regards,
Scott

Seems that when Leupold was posting here, he mentioned that you could use a different combination of bases to accomodate this problem . It seems like it was a Remington rear and a Winchester rear base would work as one is approx. .020" higher than the other.

If you could do a search you might find the post as it wasn't all that long ago, maybe a couple weeks. He even mentioned the part numbers required to make it work, I believe.- Sheister

Call Leupold, they'll mail you shims for free.

Hilltopper
Hate to ask the obvious... but did you try to see just how high you could make it shoot? Crank it all the way the other direction, then come back 1/2 the distance. That will give you a roughly centered scope, with an idea of how much shimming needs to be done.

I hate to say it, but it would not surprise me if you found out everything was OK. That "rightie-tightie, Leftie-Loosie" thing bites people all the time. <img src="/ubbthreads/images/graemlins/blush.gif" alt="" />

If you do still have a problem it is good to know where the center is...
art

Art, he may not have a matched set of rings for that rifle or even bases if it is not a solid base. I would check that first. Rings have a way of getting mixed in some shops. -- no

NO
Yeah, you are right, the list of possible problems is nearly endless... but notice the way everyone is politely staying off the scope brand? <img src="/ubbthreads/images/graemlins/blush.gif" alt="" />
art

Hilltopper....

I agree with Stika Deer, "center" the adjustments of your vertical crosshair by moving it all the way from the highest to the lowest setting and "count" the clicks. Then divide the number of those "clicks" by 2... and add that answer to your lowest scope setting. This will "center" the scope's reticle and give you the maximum vertical "up" or "down" scope adjustment if you still need to shim the REAR scope mount once you're "centered" the vertical reticle.

Incidentally, since the rifle is shooting "high", it's the REAR of the scope that NEEDS to be raised... it will cause the rifle to shoot LOWER. If you put shims under the FRONT of the scope, your rifle will shoot even HIGHER than it does now... not something you want it to do.

You could also put a small, very thin piece of flat lead stock inside the lower, rear scope ring. Just make sure you don't strip the scope-ring screws when you tighten the read scope rings down.

I resorted to using a thin strip of lead between the pistol's barrel and the scope rings many years ago when I "scoped" my High-Standard Supermatic Trophy 10-inch inter-changable barrel on my .22 target pistol when I started using it for small varmints (chipmonks, etc.) at less than 50 yards. It worked just fine and due to the softness of the lead, I was able to tighten the scope rings down which held very solidly against the lead I wrapped around the barrel. This was before they began making scope mounts for pistols.

I hope this solves your scope problem...


Strength & Honor...

Ron T.

Ron, you've got your shims backwards. We need the scope to point more in the same direction as the bore. I had it right in the second post in this thread.

Ron,

I don't think so. Raising the rear of the scope will make the rifle shoot higher. Go back to my earlier posts.

Paul

Have a set of custom bases made. Give talley a call.

Having mounted many scopes when I managed a gun shop, I found that often just turning the rings around would make a big difference. Try them individually, not both at once...lots easier than shims.

hilltopper, I suggest mounting the scope on another rifle and see if your zero is high on the other rifle. If it is I'd send the scope back to Burris. I'd call before sending it to them and if they say to shim the rings or bases tell them this is a known problem with some Burris scopes and repair or replacement is in order.

257Wby, a question re turning around one ring at a time. I can see where that could make a difference laterally, but have you seen that make a difference vertically as is needed in this case? That doesn't compute to me unless the ring is in need of a SERIOUS lapping job.