Adjusting Parallex on Leopold Nonadjustable Scopes

[GBertolet]

I have a 6X36 Leupold scope I want to adjust from the factory set 150 yards, to 75 yards. Parallax is pretty bad at the shorter ranges. I have the lens adjusting tool, and have done other non Leupold scopes. The 1/4" lock ring on the objective lens is on so tight, it won't come off by ordinary means. I don't know if there is thread locker on it. I have tried grip tape and gripping gloves, with no success. No slippage, but it just won't turn. I do have a rubber strap wrench to try for a more aggressive approach. Does anyone have any experience on Leupold scopes that they might share?

I talked to Leupold, and they want $75 to do this service, and figure another $20 to ship it out there with insurance. $95 is a lot of money for a simple job. I would rather not send it out if I don't have to. They used to do this service for free, charging only for the cost of return shipping. Times have changed.

[725]

Not familiar at all and don't know what fluids would migrate into, but the best "undo'er" I've ever use was a 50/50% mixture of acetone & transmission fluid. Let it soak in and it loosens all sorts of stuff.

[roysha]

I would have a lot of concerns about using any form of penetrant on a scope.

Perhaps, you could set the scope out in the sun on a bright, hot, sunny day and get it good and warmed up. If there is any thread locker, which I rather doubt there is, that might soften it enough for you to loosen the lock ring. Using some form of heat gun may create too much heat whereas the sun shining on the scope is normal exposure, more or less. I have adjust several Leupolds for 22 RF range parallax and have never had a problem getting the lock ring loose.

[lefty o]

its all fun and games til you cause a leak in the scope. letting the gases out, and the moisture in.

[ShooterAZ]

This^^^. I'd rather spend the $95 dollars, than have a useless scope.

[roysha]

This^^^. I'd rather spend the $95 dollars, than have a useless scope.

Useless, really??

[GBertolet]

I got it. I used wood blocks with a 1" groove to grip the scope body. Put duct tape around the tube for gripping and protection. Put the assembly in a vise, with a wrap of duct tape around the end cap, for gripping by a rubber strap wrench. I made the vice just tight enough so the scope would not turn. The end cap then came loose with the rubber strap wrench without further issue. The internal spanner nut took 1/2 turn to eliminate the parallax. It's perfect now 50-75 yards for my 12ga slug gun. I screwed the end cap back tightly by hand, cleaned up the tape residue on the scope with lighter fluid. It looks like new, not a mark on it.

I talked to Leupold, and this is basicly how they do it. They clamp the scope in a machine, and unscrew the end cap. As long as you don't remove the lens from the tube, you don't loose any nitrogen. There are lubricated O rings inside that are made to slide to allow this adjustment.

[ShooterAZ]

Glad you were able to get it done. This is something I would never attempt, for fear of breaking the seals.

[Kestrel4k]

I have re-done the parallax many times on a substantial number of Leupolds, and I'm not even a DIY'er type normally.

With a good set of small strap wrenches, it's just so straightforward - easier than simply packing one up & mailing out.
Have never needed to defeat thread locker or use penetrants, but yes those lockrings can be on pretty tight sometimes.

[greenjoytj]

How do you test the scope parallax to prove it is on for the range intended?

[GBertolet]

What I do, is set up an orange, scope sight in target, with the 1 inch grids, at the desired distance. Have the scope secured, that it doesn't move, focused on the target. While looking at the target, move your head slightly. If the crosshairs move along with your head, your not there yet. Keep adjusting the parallax in small increments, until the crosshairs stay put. That's it. Usually you move the lens carrier out, to shorten distance, or in to increase. It doesn't take much movement to make a difference. Often 1/4 to 1/2 turn. The 1 inch grids on the target make it easier to see the crosshair movement when adjusting.

[JoeJames]

This thread is a keeper!