I have an extra set of rings from my NULA 20 in 308.
Are these by chance usable on the Fieldcraft, Forbes or CLR rifles?
Yes to all of them except I am not sure about the Barret. The original ones were on the Forbes tooling but not sure now if they got changed from the prototypes. I looked on the Talley sight and the SKU #s were different for the Barret and the Colt Light Rifle so still not sure.
No on Barrett but they should fit the others.