can you use a weaver mount on a picatinny rail
The military standard, MIL-STD-1913 ``Picatinny rails'' date from the mid-1990s and have very strict military standard dimensions and tolerances. The Picatinny rail has a similar profile to the Weaver, but the recoil groove width of the Picatinny rail is 0.206 in (5.23 mm) versus 0.180 in (4.57 mm) of the Weaver rail/mount , and by contrast with the Weaver, the spacing of the Picatinny recoil grove centers is consistent, at 0.394 in (10.01 mm). Many 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. because the Picatinny locking slot width is 0.206 in (5.232 mm) vs the .180 width of the Weaver, and the spacing of slot centers is 0.394 in (10.008 mm). Because of this, with devices that use only one locking slot, Weaver devices will fit on Picatinny rails, but Picatinny devices will not always fit on Weaver rails.
Weaver rail mount