Home Forums Hunting & Shooting Gunsmithing Help, ran out of adjustment on optic

I'm trying to sight in a rifle and ran out of adjustment when I got 4 inches below point of aim. I'm using low rings so if I used med or high rings would that help? I can't see how going higher with the optic would help but I'm probably confused. Any advice would be much appreciated.

What rings and bases? You could go to a 20MOA setup or I'd probably start by lapping the rings, centering the crosshairs in the scope and then resighting in.

Are the proper bases on the rifle in the right orientation?

If you can, try a different scope. If you have the same problem it's your mounts or rifle. Burris Signature rings have plastic inserts. The offset insert kit will allow you to correct for the problem.

I believe they are talley quick release rings with bases. The bases look like they are in the correct places. This is a pre 64 winchester model 70 action they are on. I bought the gun last week with the scope, rings and bases on it. Shot it yesterday and had this problem so I put a known good trijicon scope on it and this morning had the same issue.

Burris Signature rings with offset inserts should cure your problem.

Thanks guys

Won't cure the problem per se but may allow you to center the scope.

If that's right, figure out what the problem is and fix it. Shimming one way or another (that's what the Burris rings do) is a bubba fix IMHO. (But that's just me.)

So if I'm shimming or using the Burris rings the rear needs to go up some to raise the point of impact, is this correct?

Yes. In your mind see a line from the muzzle to where the bullet impacted. And see a line from the scope to where you aimed. Then see how the scope has to move so the aim point ends up at the point of impact.

good description right there...

You bore sighted first, right?

When I had this problem I determined which base I needed to shorten a tiny bit and then lapped the base against the receiver with sandpaper on it. It won't take much. Just go slow and keep checking.

Not exactly correct to shim the scope. Puts stress on the tube. Better to shim the bases as needed. Best of all is a tapered base.
Ring height means nothing and the lower to bore the better.

Furthermore, shimming the bases should only be done enough to bring the ring holes into alignment with each other. If you go farther than this in an attempt to Bubba up a canted base effect you're putting the scope in a bind.

Indeed. Check to see if the right bases are on it.

Some years ago I ordered a set of bases from Brownells which just didn't work. Compared them to the ones already on a similar rifle. Turned out to be a misprint in the catalog....

The Burris inserts are not the same as shims, because they do not stress the scope. The beauty of the Burris inserts is that they are curved, and pivot in their recesses, so stress on the scope tube is eliminated or at least reduced. Shimming places one ring out of parallel alignment with the other, so that the scope is contacted by one edge of the ring, which is a common source of ring marks.

Another way to deal with this situation is to build up one ring bottom with epoxy, so that there is full contact with the scope tube. I do it in a couple of steps, starting with a shim using a narrow strip of tape, then remove the tape strip and add a second coat of epoxy for full coverage. A bubba solution, but done carefully it works and is neat.

Paul

The Burris setup is pretty neat, might cost some, but you'll save your time.

You should make DANG sure you have the correct bases, but because this is a Model 70, it might be the way the receiver was put together way back when. But if it's in fact correct, then ---

I would get out the calculator, center the scope adjustments, fire a round, measure THAT below point of aim, divide distance of shot by distance between rings, and that will give you a good number of how much you have to shave, shim, or both.

Then, after you've put the bases back down, you will pretty much have to lap the daylights out of the rings to keep the scope happy.

Anybody know what number leupold std bases should be correct for a pre 64 model 70? I put some 50023 on and the rear base is about .0035" lower than the front if I put a strait edge a cross them. This is the problem but I need to figure out which ones are correct.