I was thinking of interesting flash suppressors to add to my current build (A1 sights, M4-barrel, Dissipator w/ ACE shorty stock), and wondered if the older style of M249 SAW flash suppressor is compatible with the AR15.

IIRC, I've seen both the A2-style FS and an FS that was rather bulbous (like an onion or tulip bulb).  I believe I only saw the A2 style while serving in Iraq, but saw the older style FS on the beater training gear while in the schoolhouse.  

Am I recalling correctly?  I tried tracking down info on Google, but wasn't finding what I needed.  

If I am recalling correctly, is this FS compatible with the AR?  It'd tend to guess it might be, since the current SAW FS appears to be just the regular A2 FS.  

If it is compatible, is there anwhere I can buy such an FS?  I assume that it would be more or less as effective as the A2;  I assume it was changed for ease of mounting accessories, which I don't plan to do on my AR.  Just seems like it would be a distinctive touch for an AR without many downsides.

Thanks for any info,  -MV