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Weaver Rails vs. Picatinny Rails

2020 SHOT Show - rails

So you have a new scope that you want to mount on your rifle. The scope came with a set of rings that are Weaver-style.

All you need now is a scope base and you will be set to mount the scope on your favorite firearm.

When you start looking for scope bases, you will find two styles that look the same in the pictures, but are not the same.

One is called Weaver and the other Picatinny (MIL-STD-1913). These two rails, in many cases, can be used interchangeably.

Weaver vs. Picatinny: What’s the Difference?

The main differences between the Weaver and the Picatinny rails are the size of the cross slots and the slot spacing.

Weaver rails have a slot width of 0.180″ (4.572 mm), but are not necessarily consistent in the spacing of slot centers.

The Picatinny rail has a slot width of 0.206″ (5.232 mm) and the spacing of slot centers is always 0.394″ (10.008 mm).

Because of this, Weaver devices will fit on Picatinny rails, but Picatinny devices will not always fit on Weaver rails.

So those Weaver-style rings that came with your new scope will work on both styles of rails.

If the scope has been supplied with Picatinny-style rings, you will most likely be limited to only the Picatinny mount.

The difference between Weaver and Picatinny Rails is fairly minute, so if you are capable with a Dremel or file you may be able to make Picatinny devices fit on a Weaver rail.

Rifle with a scope

Weaver Rail Basics

Weaver Optics has produced scopes for decades. The founder, William Ralph Weaver, also designed the Weaver rail as a mounting system for his scopes. The Weaver rail came before the Picatinny.

Additionally, when Weaver rails were introduced, they were made in two separate pieces. One piece would go on the front of the receiver and the other would attach to the rear for scope mounting.

This two-piece design allowed the bolt opening to be free from obstructions, allowing cartridges to be inserted easily and for the use of stripper clips.

Now, Weaver rails can be found in both one-piece and two-piece variants depending on your preferences and needs.

Weaver Rail

Picatinny Rail Basics

Picatinny mounts and rings will most commonly be found on products that were originally designed for military use and have found their way into the civilian market.

For instance, the top rail on an AR-15 (the civilian version of the U.S. M16 battle rifle) flattop receiver is a Picatinny rail. You are able to use both styles of rings on this rifle.

In addition to long guns, Picatinny rails can be found on some handguns. Some handguns feature a Picatinny rail along the top of the slide for mounting a red-dot sight.

Most modern handgun manufacturers incorporate a rail on the front section of the frame for weapon lights and lasers. This is referred to as an accessory rail.

Some manufacturers include an accessory rail, but don’t use the Picatinny design. For example, GLOCK and SIG Sauer handguns have their own proprietary rail designs that are not interchangeable with the Picatinny rail.

However, many companies design their products to be compatible with both different styles of rails.

Picatinny Rails

Conclusion: Weaver Rails vs. Picatinny Rails

Both of these rail systems have their share of popularity among shooters, but you’re more likely to find a Picatinny rail on modern firearms.

The popularity of the Picatinny rail is partially because of the adoption of the rail by the U.S. Military in 1995, but also because the consistent spacing makes them a better option for swapping accessories between guns.

Which style of rail do you prefer and why? Let us know in the comments section below!

Editor’s note: This post was originally published in April of 2011. It has been completely revamped and updated for accuracy and clarity.

About the Author:

Alex Cole

Alex is a younger firearms enthusiast who’s been shooting since he was a kid. He loves consuming all information related to guns and is constantly trying to enhance his knowledge, understanding, and use of firearms. Not a day goes by where he doesn’t do something firearms-related and he tries to visit the range at least a couple of times a month to maintain and improve his shooting skills.

His primary focus is on handguns, but he loves all types of firearms. He enjoys disassembling and reassembling firearms to see how they work and installs most of the upgrades to his firearms himself, taking it as a chance to learn. He’s not only interested in modern handguns and rifles, he appreciates the classics for both historical value and real-world use.
The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (25)

  1. I am attempting to mount a modern (Weaver or Picatinny) mount to an old Model 512 Rem .22; but the dovetail on the gun is only 7/16 wide too narrow for the newer scope mounts. Is there a conversion rail that can be mounted to the old dovetail that accepts the picatinny mounts?

  2. Hi. Please elaborate on the width and angle of face cut of weaver and picatinny and also the width of scope rings. I have a Mosin with builtin dovetail and would like a narrow set of rings.
    PS: pictures are always a great help.

  3. How do these rails go on? I have a pumpaction shotgun, i think its a remington or winchester. Not a combat shotgun just a refular. But i want to put a reflex or a red dot site on it.

    Is this something i can order and it come with a kit that makes it mountable on any barrel or surface?

  4. I have a rem 700 varment with a weaver style mount and ring. I am having problems with the scope hitting me when I fire the rifle. I have made adjustments to the eye relief setup with no discernible difference. I am thinking if I change to a pica tinny rail, I may be able to correct this issue. Any assistance with this problem would be greatly appreciated.
    Michael v

  5. Thank you for explaining this. I knew there was some ability and limitations to interoperability between the two, but you put it quite well.

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