I've read of the plumb bob trick here where one hangs a plumb bob from something and lines the vertical crosshairs of the scope with the sting to get the scope level.  But how do I make sure I have the rifle perfectly level before I fasten the two?

I have a Tipton gun vice but it has no bubble levels on it like some of the nicer ones I see in the store.  Even though the vice holds the rifle tightly at he buttstock, it seems that it is still not holding it truly level.  The only way I can think to verify and adjust its level is to place a small (6" - 12") level on the AR flat top, balancing it at its middle at a 90 degree angle to the mounting rail.  Has anyone tried this?  Is there a better way to do it?

Many thanks for any help provided.
 

I remember seeing a small level that mounts to the flat top. I don't remember where I saw it, but it shouldn't be too hard to find.

Steve.

US OPTICS has a nice 1913 rail mounted level.

top

While at Wally World the other day, I found a level with built-in laser.  It costs about $39.  It has a magnetic base and a laser that can be configured to project a dot or crosshairs.

For an AR flat top, before mounting your scope just slap the level on top of the rail (laser pointing forward over the muzzle), turn the laser on with the crosshair configuration, and line up the laser with a straightght line (use indoors only as the laser is not bright enough to use outdoors) such as a door frame, wall corner, etc.

Firmly secure the gun in this orientation (the Tipton Gun Vise works fine for this).

Mount your scope and align the vertical crosshairs in your scope with the same vertical feature to which you aligned the laser.  If you did not move the gun during the scope mounting process:

Voila!  Scope and gun are aligned!

Note:  This only provides vertical alignment and is NOT a method for bore sighting.

Note 2:  As long as the scope, rifle and laser are aligned to the same straight line feature, it is not necessary that the feature be perfectly plumb.

HTH