I would like to begin by giving the good folks at Vortex Optics a big thank you and it is great to know that a company still stands behind its guarantee. I had a problem with my scope, I called customer service, mailed it in and had a new optic back in less that five business days.
The beauty of the Picatinny rail system is the ease in which you can add all kinds of stuff to a firearm that has the rails on them. If you are mounting a scope that does not have integral mount on it you still have to do a little work to do.
If you mount more than one scope a year you will want to invest in a Wheeler scope mounting kit it is a bit pricey especially if you add the 30mm tool but well worth it. It comes with an inch lbs torque driver, fixtures for smoothing out 1″ and 30mm rings, thread locker for your bases if mounting to a non Picatinny rail, and what they call the level,level,level.
Also go ahead and buy a gunsmith screwdriver set Wheeler makes a good set as does Weaver, and B Square you can go crazy with these sets with some offering 70+ bits. The bits work better than the supplied allen wrench. If you do not have this kit you will need the allen wrench that comes with the mount, an inch pounds torque wrench with socket adapter and a good selection of sockets, a small level two if you have them.
You need a work space that you can lock your rifle into to ensure that everything is level. There are a ton of gun maintenance vises out there but MTM makes some good affordable products and there are any number of bench vises that will work. If you do any amount of work on ARs and you have a work bench and vise spend the money on armorers blocks. They will pay for themselves many times over especially after your first build.
Mounting the Scope: I mounted a Vortex Crossfire II using a 1″ Primary Arms Deluxe AR one piece scope mount
Step 1: Unload the weapon then check it again to make sure. Lock the rifle into your vise fixture or your rest. Clean your rails and the attachment point(s) on the mount to insure no debris or gunk is on them. Nothing is more frustrating that some little something keeping you from leveling your mount.
Step 2: Smooth out the inside of the scope rings. Follow the instructions provided in your Wheeler kit. This makes sure than any ridges or high spots created in the manufacturing process of the rings get removed. This allow for the entire ring to grip the optic which gives you the rigidity you need for accuracy. If you do not have the de-burring fixtures I personally would not attempt this step. You could removed too much metal and ruin the rings.
Step 3: Attaching the mount, this is where it can get a little time-consuming. Separate your rings and put the screws and tops to the side in a box or other place you will not lose them. Put your scope mount on the rails as far forward as it will go while still being in full contact as you do not want part of your mount hanging off and hand tighten (as you might have to move it), then put the scope in the bottom rings. Next set up your normal cheek weld and starting with scope as far forward as it can go move it towards your eye until you get the full view thru the scope. Remove the scope and now make sure the mount is level with the rifle then lock your mount down to the rails using your torque wrench tighten to the manufacturers specifications. Do not over tighten as you can damage the mount or screws. If your attachment screws are big enough for a socket use one and not the screw driver slot.
Step 4: Establishing eye relief, with the mount ready to go put your scope back into the open bottom rings and reestablish your full field of view. Now put the top of the rings down and screw down enough to where you can still move your scope. Now level the scope with the mount. I use the top cap on the scope as that gives a flat surface for the level and put another level on the mount. Now move the scope until it is level. Re-check your eye relief and tighten your ring screws. Again tighten only to the manufactures specifications do not over tighten as you can knarf up your screws. You do NOT need to use thread locker. If you do not have a torque wrench hand tighten until the screws stop do not try to force it. For example the screws that came with my mount are only tightened to 20 inch pounds.
You are now ready to boresight the rifle.