A friend of mine got these along with a used rifle he just purchased.  Does anyone know anything about them.  

The first one is a two chamber compensator with ports on the sides.  

http://i30.photobucket.com/albums/c346/rideandshoot/100_2705.jpg

The second one has a single expansion chamber fwd of the crown with multiple small exhaust holes on the top then there is a A2 style flash hider in front of the expnsion chamber.

http://i30.photobucket.com/albums/c346/rideandshoot/100_2706.jpg

We were wondering if they would be worth trying.

That second one looks like a DPMS "Fabio" which I think is considered more a stabilizer for recoil and muzzle climb. Not sure what it would do as far as muzzle flash.

The first one looks familiar but can't place it.

ETA: On the first one, maybe John Masen(I think that was the name) made something like that. I'll do some googling and see what I can't turn up.

The first compensator looks very similar to the post-ban Armalite/Eagle "Miculek" style compensator. My Armalite comp had slots like that, but I don't think it had the "recess" on the top, I believe it was flat. Take a look at pics of OEM Armalite compensators and compare what you have to that...that may be a good place to start.
ETA: I am glad I can't remember that post-ban crap-comp very well. Use them as paper weights and get an A1 FH or Vortex.

The second photo is a DTA Mil-Brake, made by Fabian Bros.  They worked ok for controlling muzzle flip, but are a pain in the ass to clean....   I think that brake is circa 1986

The two chamber brake could have been made by several companies.  That 2 chamber brake works well, but will be noisy for adjacent shooters.  On a short barrel it will really get LOUD.


Lem