The Picatinny and Weaver Rails are two accessory platforms which are currently used on various firearms. Weaver accessories can be mounted on Picatinny rails but it cannot be said for the latter.
The Weaver rail was created by William Ralph Weaver. He founded Weaver Optics in 1930 and his Weaver rail mounted optics were very popular at the time. The modern Weaver rail however is an innovation from the ones that came out in WW2 for the Springfield 1903A4 rifles. The Picatinny rails on the other hand are the standardized evolution of the Weaver system. The Picatinny rails were developed in the Picatinny Arsenal located in New Jersey, and they were adopted by the US military under MIL-STD-1913 in 1995.
Picatinny and Weaver Rail Differences
Slot Width
Picatinny – 0.206 in (5.23 mm)
Weaver – 0.180 in (4.57 mm)
Spacing of Slot Centers
Picatinny – 0.394 in (10.01 mm)
Weaver – Inconsistent
Though they may look the same the at first glance they are two different rail systems. Since the adoption of the Picatinny rail as the military standard many accessories have been designed specifically for the Mil Spec rail. Although not as widespread, Weaver accessories are also available in the market and these also work on the Picatinny rail. Just remember Weaver accessories work on Weaver and Picatinny rails but Picatinny accessories don’t work on Weaver rails.
One Last Tip
If there’s anyone that knows the AR-15 platform, it’s the US military. As a special offer for our readers, you can get the Official US Army Manual for AR-15/M4/M16 right now – for free. Click here to snag a copy.
