Re: F T/R bipod limitations?
There are limitations on what sort of "support" you can put under your bipod, but surprisingly few limitations on the bipod itself. Ive seen anything from 4# monsters out of Canada to 5-6oz one-piece carbon fiber constructs. That's the beauty of the 18.15 lb. weight limit, it encourages people to branch out and try new equipment. If you want a 4# pod, you need to run something else lighter, it's all a balancing act, and encourages development.
Some things that would NOT be allowed: anything that restrains your bipod feet, or channels their recoil path (as we have seen on the line on occasion).
Darrell