I have some experience with an equivalent design in New Zealand.
The modular Rebel design is similar to a design that has been selling out of New Zealand and the UK for about five years.
http://www.dpt.co.nz/category.php?id_category=12
Given the State Department ITAR restrictions no suppressors from outside the States get in and no suppressors from within get out. This means the US market for suppressors is a closed shop and has developed independently from the rest of the world.
The Rebel SOS counters the abrasive wear on aluminium by swaging a steel section near the centre hole. The NZ suppressor has a modular segment that is entirely made from stainless steel designed to be the first segment fitted closest to the muzzle. They both do the same thing to increase the life of the suppressor while keeping the weight down. While stainless steel weighs twice as much as aluminium it's harder wearing and takes the brunt of the blast and pressure. Both the Rebel and the NZ designs weigh about the same as a titanium suppressor but are much cheaper. They are not however full-auto rated.
The modular design makes for easy cleaning in a standard size ultrasonic bath. The one in the picture has a 5" over-barrel section;
[ATTACH=CONFIG]10737[/ATTACH]
The segments do not come apart while shooting if you are worried about that. Quite the opposite, they carbon-up and bind. This makes it hard to unscrew them afterwards. The NZ designers sell a purpose wrench to help here but a couple of wood chocks drilled with a hole saw works just as well. That said, if you crack them loose by hand after every session and keep the threads greased you won't need it;
[ATTACH=CONFIG]10736[/ATTACH]
Adding segments makes it quieter but frankly after 6 the reduction of extra segments is barely noticeable to the human ear (with muffs on). Also the cumulative effects of machining run-out start to make adding segments more risky of baffle strike. The NZ manufacturer recommends limits to the number of segments. The Rebel design segments look a little wider than the NZ design.
The NZ version works and seems as quiet as any suppressor I have used. I say seems as I don't have a sound meter and am sceptical of manufacturer claims to sound reduction. I have yet to see an objective comparison between manufacturers under the same conditions. The videos on Rebel's website are interesting and go a long way to convincing me how efficient these devices are. Also we need to be mindful that the Decibel scale is logarithmic, not linear. By that I mean a 25db reduction from a peak of 167db is not a 15% reduction in sound (that would be linear). It is much more. Arriving at 141db is a fair reduction but is still not hearing safe. But then no manufacturer in the world makes a high-power, centre-fire suppressor that is 'hearing safe'. 'hearing safe' is also dependent on whether we are talking about low db's over an extended period or higher db's over a short time. All high-power suppressors are around the 130db+ mark which even in short impulses like rifle shooting is still dangerous to unprotected hearing.
The US paperwork and time delay requirements shave a little of the modular utility off this stacked design. As I understand it once you get your licenced suppressor you cannot simply buy replacement segments without starting the whole process again, yes? I suspect they want another $200 tax as well. In NZ you can buy suppressors and replacement segments whenever you like without the government getting involved. This enhances the benefits of a modular design.
The modular Rebel design is similar to a design that has been selling out of New Zealand and the UK for about five years.
http://www.dpt.co.nz/category.php?id_category=12
Given the State Department ITAR restrictions no suppressors from outside the States get in and no suppressors from within get out. This means the US market for suppressors is a closed shop and has developed independently from the rest of the world.
The Rebel SOS counters the abrasive wear on aluminium by swaging a steel section near the centre hole. The NZ suppressor has a modular segment that is entirely made from stainless steel designed to be the first segment fitted closest to the muzzle. They both do the same thing to increase the life of the suppressor while keeping the weight down. While stainless steel weighs twice as much as aluminium it's harder wearing and takes the brunt of the blast and pressure. Both the Rebel and the NZ designs weigh about the same as a titanium suppressor but are much cheaper. They are not however full-auto rated.
The modular design makes for easy cleaning in a standard size ultrasonic bath. The one in the picture has a 5" over-barrel section;
[ATTACH=CONFIG]10737[/ATTACH]
The segments do not come apart while shooting if you are worried about that. Quite the opposite, they carbon-up and bind. This makes it hard to unscrew them afterwards. The NZ designers sell a purpose wrench to help here but a couple of wood chocks drilled with a hole saw works just as well. That said, if you crack them loose by hand after every session and keep the threads greased you won't need it;
[ATTACH=CONFIG]10736[/ATTACH]
Adding segments makes it quieter but frankly after 6 the reduction of extra segments is barely noticeable to the human ear (with muffs on). Also the cumulative effects of machining run-out start to make adding segments more risky of baffle strike. The NZ manufacturer recommends limits to the number of segments. The Rebel design segments look a little wider than the NZ design.
The NZ version works and seems as quiet as any suppressor I have used. I say seems as I don't have a sound meter and am sceptical of manufacturer claims to sound reduction. I have yet to see an objective comparison between manufacturers under the same conditions. The videos on Rebel's website are interesting and go a long way to convincing me how efficient these devices are. Also we need to be mindful that the Decibel scale is logarithmic, not linear. By that I mean a 25db reduction from a peak of 167db is not a 15% reduction in sound (that would be linear). It is much more. Arriving at 141db is a fair reduction but is still not hearing safe. But then no manufacturer in the world makes a high-power, centre-fire suppressor that is 'hearing safe'. 'hearing safe' is also dependent on whether we are talking about low db's over an extended period or higher db's over a short time. All high-power suppressors are around the 130db+ mark which even in short impulses like rifle shooting is still dangerous to unprotected hearing.
The US paperwork and time delay requirements shave a little of the modular utility off this stacked design. As I understand it once you get your licenced suppressor you cannot simply buy replacement segments without starting the whole process again, yes? I suspect they want another $200 tax as well. In NZ you can buy suppressors and replacement segments whenever you like without the government getting involved. This enhances the benefits of a modular design.