Tri Rail Questions

[r.r149]

Is the tri-rail a spec picatinny rail? I tried installing a streamlight protac and the installed picatinny mount on the flashlight fit the tri-rail. I also tried to use a Larue qd scout mount and it still doesnt fit correctly. The rail seems too small and most accessories I mount seem to be wobbly.

Also is there a specific torque on the screws to mount the trirail to the handguard?

Thank you everyone!

[apex]

Is the tri-rail a spec picatinny rail? I tried installing a streamlight protac and the installed picatinny mount on the flashlight fit the tri-rail. I also tried to use a Larue qd scout mount and it still doesnt fit correctly. The rail seems too small and most accessories I mount seem to be wobbly.

Also is there a specific torque on the screws to mount the trirail to the handguard?

Thank you everyone!

No, they are not MIL-STD-1913 (picatinny) rails, they are Weaver rails. Picatinny rails will measure 0.206" between the rail slots, while Weaver rails measure 0.18" between slots. There is general compatibility between the two, but certain specifically-designed picatinny accessories will not fit a Weaver rail.

Usually the lower-end/less expensive market caters to the Weaver rails while the high-end/expensive market caters to picatinny standards (and a lot of the lower-end products will claim to be picatinny just to mimic the look of picatinny, but a set of calipers will tell you otherwise).

EDIT:
Well... this is embarrassing...
...after asking a friend in the industry to check the rails just to be sure with his $300 set of calipers...
...it turns out my calipers are off by 0.03".


So, these are in fact MIL-STD-1913 rails. Why your mounts don't work I have no idea.
Off to write an angry letter to the manufacturer now.

[ChalupaCabras]

You're all talking about 'Mil Spec' rails ... That exists, but none of the manufacturers can agree how to interpret that, and each spec has different tolerance built in. The rail probably meets a version of the Spec, just not the same one your streamlight uses.