I wonder if you could do just a wrist wrap, maybe an ace wrap thingy?
What are the actual symptoms? I know we may be getting off topic a little, but it almost sounds as if there may some other underlying issue.
Firearms and shooting doesnt bother me, as long as I'm not white knuckling my guns and I take breaks periodically. Other high impact things do. I get to where I cant grip much of anything and in fact, just trying to grip something for long periods of time (like my MIG and TIG guns at work) will cause my hands to not work. I used to do quite a bit of leather work, but just holding the tools proved to be near impossible.
So, again out of curiosity, what are the syptoms, like pain in certain parts of your hand? Unable to grip anything else from fatigue?