Picatinny Scope MountThe Picatinny scope mount is based on the original Weaver design. The main difference between the Picatinny and Weaver mounts is that the Picatinny mount is built to exact specifications and tolerances so that they're a universal system. All Picatinny-mount scopes will be interchangeable.
Three to 4 inches is about right. You must focus the eyepiece (ocular lens), and thus the reticle, on every new scope. Point the scope at a uniform surface just a few yards away to see the reticle clearly.
Compatibility with PicatinnyMany rail-grabber-mounted accessories can be used on either type of rail, and accessories designed for a Weaver system will generally fit Picatinny rails – although not vice versa. 180 width of the Weaver, and the spacing of slot centers is 0.394 in (10.008 mm).
Cabela's will mount and bore site for free while TJ's will mount and collimate my scope for $50.00 (I don't even know what collimate means). Would I get better results from a gunsmith?
Eye relief is the distance from the outer surface of the eyepiece lens to the position where the exit pupil is formed (eyepoint). Looking through binoculars from the eyepoint, you can obtain the whole field of view without vignetting.
The two major areas where the picatinny rail differs from the weaver style are the number of slots, the slot placement and the slot dimensions. the basic difference between the weaver and picatinny slot dimension is that the picatinny has a slightly wider, and slightly deeper slot.
What size scope should I buy? Scope tube diameter should only be a consideration if you're routinely shooting at distances beyond 500 yards, which is where 1 inch scopes will start running out of internal adjustment. If you're not shooting long distances, a 1 inch scope will do just fine.
The knob on the right side of the scope is generally an adjustment for windage, which means how far right or left the projectile will strike. If you rotate the windage knob three clicks to the left, the bullet will strike 3/4 inch to the left.
Drilling and tapping are two different actions. Drilling refers to creating a smooth hole in a material with a drill and motor. Tapping is the action that creates a thread into the side of the hole.
A Picatinny rail has specific dimensions of grooves and notches and is built into a handgun or long gun to mount different attachments. It's sometimes called a “Pic Rail†and is exactly the same thing as a MIL-STD-1913 rail.
Picatinny MountsThe Picatinny mount is perhaps the most popular type of mounting system for scopes because it has universal, standardized measurements. Due to this, many manufacturers make accessories to fit any Picatinny mount. While Weaver accessories can fit Picatinny rails, there is some play in the fitting.
The United States Army, Air Force and Marine Corps field the Trijicon TA31RCO ACOG, a 4× magnification model with a 32mm objective lens (4×32), with specially designed ballistic compensating reticles that are fiber optic & tritium illuminated, for the M4 carbine and M16A4 rifle.
