Both the Browning and Ruger systems are external tubes with internal thread mated to external thread on the barrel. They are secured with a pattern of set screws, probably brass tipped.
The video I've linked to below shows the Mini-14's dampener (a very large weight) had to be adjusted almost to the end of travel backward, where the forward end of the 6" long dampener was a good 1.5" rear of the end of the barrel. At that position, he was getting shots through the same hole at 100 yards. Two turns forward and the pattern was 2.5 ".
The BOSS system doesn't look to have the same travel - what good is a flash suppressor that isn't on the end of the barrel?
It makes sense that the 'modes' of a complex system such as a rifle and would be hyper sensitive to all kinds of teeny tiny variables. It could even be that over-the counter ammunition that isn't of the same lot number, built on the same day, might require different settings. 2-3% variances in bullet weight, diameter, powder charge ... which are within 'spec' for the manufacturer and the average shooter would never notice, might need an entirely different position for the dampener - 2 to three turns forward or aft of ammunition of the same brand and type.
It is precisely that kind of potential variability that I think would hinder its utility in combat operations. Hard to get range time when your behind enemy lines - I would think. That's really why I asked the question in the first place, to see if a military system had been developed to beat the variability problem.
Here's the video:
