Oh boy, there's a lot of IANAL being tossed around. The rifle can fire with the stock off but I don't think my hip fire technique is as good as Arnie.
I was not aware of the OAL aspect. The rifle is a sig 556 scm, which is a sig 556 variant that is designed for states like ma/ct etc. It does not feature the standard 556 lower which accepts the folding stock, but rather has a dummy buffer tube, despite the piston mechanism out front. The barrel is 16, of course, and the action is close to 10" behind the chamber so I think I am quite close to the 26" OAL requirement.
My thought is basically to shorten the dummy buffer tube to a point where the overall length of the rifle is 26", and use a two-pin captive pin system to attach and detach a fixed stock. I imagine I can still shorten the rifle by at least 10" for transport.
What are some other quick detach systems that people have encountered which can resist multi-directional torque?
A few mechanisms I'm considering are:
- integrate the female trilug adapter into the buffer tube and use the male end on the stock. the standard hk tri-lug is a much thinner diameter tri-lug than the locking system in a ruger take-down for example. The hk style trilug is easy to source but another kind? I think it should be pretty easy to do a mock-up of this / weld something together.
- Arca-swiss style camera plates. These are robust and will slide in, and lock down with the twist of a cammed nut. The benefit here is it may allow adjustment vertically for improved cheek-weld, which does not seem to be an issue legally.
- captive pins as described above
- some kind of tent-pole approach