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How to Mount a Rifle Scope on a Picatinny Rail?

How To Mount A Rifle Scope On A Picatinny Rail?

The Picatinny Rail (Pic Short Rail) is also identified as the MIL-STD-1913 Rail. Pic rail is a rail interface device that acts as a mounting platform (of the military standard) for firearm accessories. 

It was initially used for the installing of scopes above the receivers of larger rifles. The Pic Rail is a fundamental yet revolutionary accessory mounting platform that is attached to all sorts of items – in particular optics – to your weapons.

Mount A Rifle Scope On A Picatinny Rail

The Picatinny Rail is by far the most widely used tool today for the shooting of guns. Many styles and variants of rifles come with a pre-assembled scope on the Picatinny rail and not only keeps the weapon lightweight but also saves you time to personally mount the scope. In order to fix the optics at the same spot for the next use, the Picatinny rails are numbered. Inability to use the same slot can lead to shifts in the point of impact.

A mechanical designer, who was leading the Picatinny team took the measures and produced an average set of numbers set on a 45-degree inclined surface and then transferred the requirements to the manufacturing facility to be inspected. The finished prototype was then sent to the technical data section for more determination, by the team. After it was decided that the new rail was to be a standard, not a specification, the MIL-STD-1913 was adopted and enclosed in 1995.


  • The rail’s design is similar to that of a stip, which is formed on a hexagonal top, undercutting and establishing a “flattened T”. This allows an attachment to glide into a perfect position from one of the ends of the rails.
  • This design is similar to the prior commercial Weaver rail mount used to mount telescopic sights, the only difference is that it is taller and the slots are wider and consistent throughout the range. The width of the Picatinny locking slot is 0.206 in (5.23 mm). The slot core spacing is 0.394 in (10.01 mm) and the depth of the slot is 0.118 in (10.01 mm) (3.00 mm).
  • The slot is comparatively wider and extensive in comparison to other types of mounts.
  • The Picatinny rail is primarily thicker than a 2-piece mount.  This structure provides relief of the ejection port which is positioned at the bottom of the base.
  • Normal slot spacing of Picatinny Rails can be found throughout the length of the mount. 


Because of their numerous applications, Picatinny rails and accessories have substituted iron sights in the configuration of many rifles, and they are often on the inner side of semi-automatic gun frames and grips. Their versatility has led to their use in paintball and airsoft.

The size and shape of the slots are the only major difference between the Picatinny rail and the Weaver rail (pic rail’s equivalent), the Picatinny rail has square-bottom slots, while the Weaver rails provide rounded slots. 

An accessory built for the Weaver rail fits into the Picatinny rail unless we modify the slots of weavers rail to square slots, we cannot use Pic rail’s accessory on this. 

Created for mounting different sorts of heavy scopes, extensive accessories and fittings are available and the rails are no longer restricted to the rear upper surface(receiver) long arms and instead fixed on or machined on the upper surface, side, or lower surfaces of all types of firearms. From crossbows to handguns and long arms including that of anti-material rifles.

The weaver rails generally have a split width of 0.180 in (4.57 mm), this width is not certainly in tune with the centre spacing of the slot. While several of the accessories are created to fit both  Weaver and Picatinny rails, most devices made for Picatinny rail do not fit Weaver rails. 

Since May of the year 2012, the majority of the mounting rails have been moulded according to Picatinny standards. 


The following are the advantages of choosing Picatinny Rail for your rifle:

  • It comes with a handy locking bar that avoids more surface contact, which is usually the case with the other rails.
  • The canting issue face with bipod rails can be avoided through these.
  • Since the Picatinny rail has close spacing, you can tweak the mounting in a number of different ways and thus enhance your vision and grip while you’re in the shooting range or hunting expedition.
  • It is more straightforward to install the scope


Scope Mounting Process

Now the significance and the advantages of the Picatinny rails are clear. Let us dig down deep into the process of mounting the scope at home.

  • Unbolt the Picatinny rail’s rings. Remove the tops of the rings so you only have the bottoms.
  • Prior to initiating the mounting process, mark the upperside’s ends and the same of the lower side. This step is important to prevent mixing up of both sides after mounting the scope of your choice. To do this, trace the ends (you can use a piece of tape) to mark and ensure that the ends go in the right place.
  • Gently put the rings on the rail. Do not screw the rings yet. Adjust the alignment of the scope. At this point, you can secure the rails enough to hold them in place, and at the same time, you have some room for adjustment.
  • Gently, keep the scope on the top of the rings and adjust the eye relief till it is perfect for you.
  • Carefully change the position of the gauge as per the form and shape of your scope to ensure that it sits in the correct position upon the rail. 
  • In accordance with your requirement, the power of the scope can be adjusted to its maximum.
  • As far as the distance between both the rings is concerned, you can get a better understanding of the guide that arrives with the rail, since some of them need you to place the rings near to the turrets, and others do not. The adjustment of the rails greatly depends on the type of rail you are working on.
  • Now, using a torque driver, begin tightening the screws on the rings. First, establish the requirements, and then based on that, you can change or pick the torque. 
  • Ensure that the ridge of your ring fits in the rail towards the forward. It is important to safeguard the scope from the backward thrust caused due to recoil.
  • Confirm that the crest of your ring fits in the rail forward. For the same reasons.
  • Be careful with rings while you tighten them. Do not play with them. 
  • The quality of a rail plays a significant role in the setup of the scope. A poor quality rail can affect the quality of your shooting and can also harm your scope.
  • Put the rings on the upper side of the scope and fasten them to their place.
  • As told in the previous step to mark the ends of the rings, it’s time to assemble the set up together. 
  • To get the best eye-relief, you will need to position the scope forward or backwards, based on your requirement.
  • Set the power of the scope to its maximum
  • Now configure the scope level by manipulating the horizontal crosshair directly down with respect to the middle of the bore.
  • At the same time, keep the magnification of the scope to its lowest.
  • In the end, tightly bolt the top end of the rings using the torque drive. This is to ensure that the scope stays firm at its position. 


To guarantee precise optics and near to 100% target acquisition, it is vital to have a suitable scope. Precisely, all Picatinny rails need to be labelled, allowing the user to restore the optics in exactly the same place each time. Being unaware of the very same will result in a slight shift in zero, which might be a huge problem if the optic is combined with a precise weapon. You will now have a greater understanding of what mount is fitted with the scope of your rifle and which choice you should take. Hurry! Get your chosen mount and set-up your scope!