Originally Posted by kcebcj
If the fella holding the rifle was to cant the rifle a little more as it looks to me the scope would be in perfect alignment with the bore and would shoot perfectly. Aligning the bore with the reticle is not brain surgery!
How come the picture did not come with the quote????
This really is a pretty simple process.
Set the rifle up. Level It. It really makes little difference if you level off of the raceway, the top of the receiver, or the top of the rail.
The whole purpose is using a level is to plum your vertical crosshair so that your elevation adjustments will always be true along the same vertical axis.
If one is convinced the leveling off of the raceway is the only way to go when setting up a rifle fine, do so. The end result will be the same either way.
All you are doing by boresighting to start with is to hopefully get your scope centered left to right before you waste a bunch of rounds down range in attempting to do so.
Even with a laser boresighter though it will be incredibly rate to get it exactly right from the beginning especially if you don't account for the height of your vertical crosshair above the bore such that your crosshair is centered about 1"-2" depending on your scope and mounting system above the point at which the laser is hitting the target.
With a system like the one I posted this thread about if you had an obvious error in level upon mounting you'd figure it out right fast because it would be impossible to get that level to match up with your raceway level which in the end could save you some serious aggravation later anyhow.
Either way if the top of your rail is not level due to eccentricities in either it's milling or that of the receiver you probably want to figure it out so you can correct for it. Without leveling off of the top of the rail you won't know that error is even there unless it's a gross error to begin with which you'll notice when tightening down the base anyhow.