I have a Browning White Gold Medallion. Yes the Boss is effective. Yes it does reduce muzzle flip. It reduces flip by allowing the escaping gases to control the muzzel flip. when it is turned in or out (tuned) it changes the frequency of the barrel. On the down side of it,it adds apparent length to the barrel and a lot of sideways blast.
As far as 30% reduction in felt recoil, I believe it, but I have no way of telling. If you unscrew the boss and shoot the rifle there is a very noticable difference in recoil and group.
I like it because it lets me shoot the bullet weight that I want to and still get a tight group.
I have a QUE tuneable muzzle brake on a Browning. It operates the same basic way. You screw it all the way in (100 clicks), then back out 50 clicks. you're now at half way. you shoot a 3 shot group then turn in 5 clicks. You keep doing this until you find the right spot.
With Brownings Boss following their instructions you go right to the correct spot(minor adjustments either in or out).
Hopes this helps

Edited by - diamond DOA on 10/26/2002 15:01:03