Scope Level and Plumb??

[Pinnacle]

So I've finally given in to the low-power variable trend for use with my SPR-ish rifle and I was wondering if anyone has any new insights to mounting the scope in the rings and assuring it is level. I've always heard about the plumb line and use of a small hand level but I have never done it myself. What do you do when mounting a new scope and rings to your AR?

BTW, the scope is a Leupold 1.5-5 with Illuminated SPR reticle and it is going to reside in the Larue LT-104 SPR mount.

Thanks a bunch.

[talbalos]

According to Wes Grant of MSTN (From TOS):


NO MORE PLUMB LINE ON THE STOP SIGN 175 YARDS FROM THE KITCHEN TABLE. NO MORE LEVELS ON THE FOREND.

MOST SCOPES LIKE NIGHTFORCE AND LEUPOLD HAVE A FLAT SURFACE UNDER THE WINDAGE AND ELEVATION TURRETS. I USE THIS AS A REFERENCE IN GETTING A SCOPE SQUARED UP IN A LARUE SPR SCOPE MOUNT, LIKE SO:

ATTACH THE LARUE SPR SCOPE MOUNT TO THE UPPER RECEIVER. I LEAVE FOUR SLOTS EXPOSED AFT OF THE MOUNT. GO AHEAD AND ADJUST THE LEVERS AT THIS POINT. I LIKE TO "WORK THEM IN" SEVERAL TIMES. NO, IT DOES NOT MAR THE RECEIVER, UNLESS IT IS SOME OUT OF SPEC THING OR PAINTED. ALWAYS APPLY FORWARD PRESSURE TO THE SCOPE/MOUNT TO SEAT THE MOUNT AGAINST THE RAIL AS YOU CLOSE THE FIRST THROW LEVER. THAT WAY, UNDER RECOIL, THE SCOPE MOUNT IS UP AGAINST THE FORWARD SURFACE OF THE SLOT.

SECURE THE SCOPE IN THE RINGS TO THE MOUNT VIA THE BOTTOM SCREWS ONLY. DON'T FORGET TO CLEAN THEM BEFORE USING THE LOCKTITE. I ONLY USE 20 IN-LB. GIVEN THE QUALITY OF THE HARDWARE, YOU COULD USE MORE. I HAVE NEVER HAD A SCOPE BUDGE THAT WAS PROPERLY INSTALLED, THOUGH.

I WOULD NEVER (!!!) DO THIS WITH CONVENTIONAL RINGS, BUT, WITH THE LARUE RINGS, WHICH REQUIRE NO LAPPING AND ARE VERY "SCOPE FRIENDLY", EVEN WITH THE BOTTOM SCREWS TIGHT, YOU CAN ROTATE THE SCOPE TO GET IT APPROXIMATELY LEVEL, AND THEN SLIDE IT FOR AND AFT TO CENTER THE W&E TURRETS. I USE MY CALIPERS TO CENTER THE W&E TURRETS PRECISELY BETWEEN THE TWO RINGS.

NOW, ONCE THE SCOPE IS CENTERED IN THE MOUNT, I TAKE A SMOOTH EDGED NARROW STEEL RULER AND PLACE IT BETWEEN THE FLAT BASE OF THE W&E TURRETS AND THE UPPER SURFACE OF THE MOUNT ITSELF. ROTATING THE RULER WITH SOME DEGREE OF PRESSURE SHOWS PRECISELY HOW MUCH ROTATION NEEDS TO OCCUR IN ORDER TO BRING THE BASE OF THE W&E TURRETS PARALLEL WITH THE TOP OF THE MOUNT. USE A LOT OF LIGHT DOING THIS.

AFTER ACCOMPLISHING THIS, I RECHECK THE TURRETS CENTERED BETWEEN THE RINGS. SOME SLIGHT MOVEMENT SOMETIMES OCCURS. IF THAT NEEDS CORRECTING, I THEN RECHECK THE SCOPE BASE PARALLEL TO THE MOUNT SURFACE. THEN, I INSTALL AND SECURE THE TOP SETS OF SCREWS. DON'T FORGET TO CLEAN THEM BEFORE USING THE LOCKTITE. RECHECK ALIGNMENT ONE LAST TIME.

THE BEAUTY IN THIS IS THAT, DUE TO THE UNIQUE PROPERTIES OF LARUE'S VERTICALLY SPLIT RINGS, THE SCOPE DOES NOT ROTATE AS THE TOP SCREWS ARE TIGHTENED. EVER. ONE BIT. NADA. ZIP. THE RINGS NEVER MARK UP THE SCOPE, EITHER.

HAVE EVER MOUNTED A SCOPE IN CONVENTIONAL HORIZONTALLY SPLIT RINGS AND BEEN FRUSTRATED BY THE INEVITABLE ROTATION THAT OCCURS WHEN YOU TIGHTEN THE RING SCREWS? THERE'S USUALLY SOME TRIAL AND ERROR GETTING THAT FIRST RING TIGHT. EVER SO SLIGHTLY ANAL TYPES LIKE ME ALSO INSIST ON THE RINGS HAVING AN EVEN DEGREE OF SPACE SHOWING BETWEEN THE UPPER AND LOWER HALVES OF THE RING, TOO. IT CAN BE A MAJOR PAIN SOMETIMES.

WES GRANT
M.S.T.N.

I've uised the technique on a couple of Larue/Leupold installations and it works.

[Pinnacle]

Thank you for your reply. I had forgotten that Wes posted this. Hopefully, it is as easy as it sounds.

[paulosantos]

I went to Sears and bought one of their Lazer Levels for around $40. I then set up my AR with the Bipod in the front and a sandbag in the rear and I level everything. I then mount the Larue mount and mount the scope. When mounting the scope, put on the bottom screws on the Larue Mount first and the scope will be tight, but you can still move it. I then place the level on top of the turret and I level the scope. Then just tighten the upper screws on the Larue Mount. It is that easy. I also mount my Aimpoint that way.