I have to second what Quick said, as I have seen a fellow at my range playing with one, and it certainly did change his results for the better, or worse, as he adjusted it. Good way of putting it - "a poor man's BOSS". You won't find people getting consistently good results with the BOSS system either: works in some applications, sometimes doesn't. Being the compulsive buyer that I am, I bought one just to fool around with it. I really don't have any rifles that I am dissatisfied with, but what the heck, maybe I'll try it, see if we can shrink some groups. I just can't get past having that donut on the barrel though. I think it was only about $12-$15, can't remember. I haven't tried it yet.
I don't know whether a big rubber band will work. I doubt I would try that.
Sims does make some claims as to the quality of their material for dampening vibration and technically some compounds are better than others for that. I have wondered what the results would be if one tried that material to bed the forend on say, a Handi or an Encore, either fully, or in pieces, just enough to keep the forend off of the barrel. I did look for some industrial vibration dampening material, but it was impregnated with an adhesive and I didn't want to muck up my forends and barrels. I think the idea might have some potential though.
