In the foreground of this photo, is this a compensator or a suppresser? Thanks anyone that can help. I'm confused due to how the end is closed off all but the hole for the round. Normal suppressors, like my others, are open at the end. Thanks again!
https://www.flickr.com/photos/114860835@N04/14714253495/

I'm not seeing your photo, but you're describing a brake.

pic fail.

Simply posting a picture of a muzzle device will not necessarily reveal its function - the internals and ports, and what it actually does are what matter.

A closed front tends to indicate either a brake, combined brake/compensator or sound suppressor.

The muzzle device on the right in your photo is a generic A2-style flash hider, which provides reduction of muzzle flash and some compensation for muzzle rise.


The device on the left looks like a DPMS Branson compensator. It's function is to reduce dust when shooting prone.


Neither is a "suppressor."

The USMC and the various manuals we received on the M16A2 service rifle referred to that part as a "Compensator"
I think the first time I heard someone call it a flash suppressor was Fineswine running her cryhole about it in the early 90s.

Military manuals have always referred to things like the M16A1 muzzle device as flash suppressors, as did the now-expired 1994 federal AW ban, which defined a flash suppressor as any device which measurably reduced muzzle flash.

A "flash hider" is properly a device which occults the muzzle flash from the operator's vision, not one which mixes in air to swirl and cool the expanding muzzle gases.

During the AW ban - brakes, and flash hiders like the conical type used on the WW2 M1 Garand rifle, were permitted, while flash suppressors like the duckbill/A1/A2 and Vortex type were banned.

Shortly after the federal AW ban sunset, people started morphing the term "flash suppressor" into "flash hider", preferring to keep the term suppressor for sound suppressors only.