Scope Rail Difference
- Thread starter FClasser
- Start date
Forum Boss
Administrator
Tom,
That's a very good question actually, and one that probably deserves BLOG coverage in the future.
The answer is that the specs are NOT exactly the same, and we have observed some rail/ring combinations that are NOT compatible. Picatinny Rails have .206",roughly 5mm) width slots, and the spacing between slots is .394",10mm) from center of one slot to center of the next. Weaver rails have a .180",4.5 mm) slot width, and, according to Brownell's: "are not necessarily consistent in a center-to-center measurement from one groove to the next." BAT Machines makes its "Weaver" rails with .180" grooves.
This is further complicated by rail makers that have used some specs that are in between. See bottom of this reply. And some sources say a Weaver rail is .150",3.8 mm) wide,Wikipedia).
This tells us that, if you buy a "Weaver Rail" it will be hard to tell just what the slot width will actually be--and it might be anything between .15 and .206" inches. You should ask the vendor for the dimensions before you buy.
The Picatinny rail is a bracket used for a standardized mounting platform for telescopic sights and other accessories such as tactical lights and laser sighting modules. The standard was first published by the Picatinny Arsenal and carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324.
Picatinny Rail Specification,Cross-section)
Picatinny Rail Spacing:
Here's what Brownell's Tech Talk says:
What are the differences between the “Picatinny†and the “Weaver†systems? The profile of the two systems is virtually identical. Depending on the quality of the machining done by the manufacturer, the two systems should be indistinguishable from the profile. The key difference lies in the placement of the recoil grooves and with width of the grooves. MIL-STD-1913,Picatinny) grooves are .206" wide and have a center-to-center width of .394â€. The placement of these grooves has to be consistent in order for it to be a true “Picatinny†MIL-STD system.
Weaver systems have a .180" width of recoil groove and are not necessarily consistent in a center-to-center measurement from one groove to the next. In many instances, a Weaver system has a specific application that it is machined for, so interchangeability is not necessarily an issue. A MIL-STD-1913 system must adhere to the specifications listed above in order for it to be considered MIL-STD, since the military desires uniformity in the recoil grooves to allow for different systems to be mounted on the weapon with no concern for compatibility.
Now, what does this mean to you? Boiled down, it means that accessories designed for a Weaver system will, in most cases, fit on a “Picatinny†system. The reverse, however, is probably not the case. Due to the larger recoil groove, “Picatinny†accessories will not fit a Weaver system. There are, of course, exceptions to every rule, but for a good rule-of-thumb, “Picatinny†won’t fit Weaver, but Weaver will fit “Picatinnyâ€.
Brownell's: http://www.brownells.com/aspx/NS/GunTech/NewsletterArchive.aspx?p=0&t=2&i=558
Reference: http://www.biggerhammer.net/picatinny/
Here is a US OPTICS "modified Weaver" rail that has .188" wide slots, and .422" spacing between slots. This is NOT to Picatinny Specs or normal Weaver:
That's a very good question actually, and one that probably deserves BLOG coverage in the future.
The answer is that the specs are NOT exactly the same, and we have observed some rail/ring combinations that are NOT compatible. Picatinny Rails have .206",roughly 5mm) width slots, and the spacing between slots is .394",10mm) from center of one slot to center of the next. Weaver rails have a .180",4.5 mm) slot width, and, according to Brownell's: "are not necessarily consistent in a center-to-center measurement from one groove to the next." BAT Machines makes its "Weaver" rails with .180" grooves.
This is further complicated by rail makers that have used some specs that are in between. See bottom of this reply. And some sources say a Weaver rail is .150",3.8 mm) wide,Wikipedia).
This tells us that, if you buy a "Weaver Rail" it will be hard to tell just what the slot width will actually be--and it might be anything between .15 and .206" inches. You should ask the vendor for the dimensions before you buy.
The Picatinny rail is a bracket used for a standardized mounting platform for telescopic sights and other accessories such as tactical lights and laser sighting modules. The standard was first published by the Picatinny Arsenal and carries the official title MIL-STD-1913. It is also known by the NATO designation STANAG 2324.
Picatinny Rail Specification,Cross-section)
Picatinny Rail Spacing:
Here's what Brownell's Tech Talk says:
What are the differences between the “Picatinny†and the “Weaver†systems? The profile of the two systems is virtually identical. Depending on the quality of the machining done by the manufacturer, the two systems should be indistinguishable from the profile. The key difference lies in the placement of the recoil grooves and with width of the grooves. MIL-STD-1913,Picatinny) grooves are .206" wide and have a center-to-center width of .394â€. The placement of these grooves has to be consistent in order for it to be a true “Picatinny†MIL-STD system.
Weaver systems have a .180" width of recoil groove and are not necessarily consistent in a center-to-center measurement from one groove to the next. In many instances, a Weaver system has a specific application that it is machined for, so interchangeability is not necessarily an issue. A MIL-STD-1913 system must adhere to the specifications listed above in order for it to be considered MIL-STD, since the military desires uniformity in the recoil grooves to allow for different systems to be mounted on the weapon with no concern for compatibility.
Now, what does this mean to you? Boiled down, it means that accessories designed for a Weaver system will, in most cases, fit on a “Picatinny†system. The reverse, however, is probably not the case. Due to the larger recoil groove, “Picatinny†accessories will not fit a Weaver system. There are, of course, exceptions to every rule, but for a good rule-of-thumb, “Picatinny†won’t fit Weaver, but Weaver will fit “Picatinnyâ€.
Brownell's: http://www.brownells.com/aspx/NS/GunTech/NewsletterArchive.aspx?p=0&t=2&i=558
Reference: http://www.biggerhammer.net/picatinny/
Here is a US OPTICS "modified Weaver" rail that has .188" wide slots, and .422" spacing between slots. This is NOT to Picatinny Specs or normal Weaver:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.