Just curious on your opinions on excessive flash.  Obviously with practice ammo it's probably a moot point...and probably a bigger consideration with those who have 16" post-ban rifles.  I know many of you practice and "load-up" with the same ammo (M193/SS-109).  
XM193/Q3131A has quite a flash, but is very popular here.  Have you considered excessive muzzle flash?  At what point, if ever, is it too much for tactical reasons?
Thanks for your thoughts.

"too much" in what regard?
blinding yourself?
'giving yourself away'?
lighting the ceiling on fire? (lol)

Yes, please clarify

Excessive flash regarding primarily hurting nightvision and secondly giving away a firing position.

Wave,

You gotta get a pre/leo lower!

With my 16", and a Vortex, I have [b]ZERO[/b] flash. S/A Battle Pack ammo, XM, Wally World Yellow Box, doesnt matter.

[i]Sometimes[/i] (read very rare) there is a [b]SMALL[/b] stringer/streamer/loose grain of unburned powder that will trail out with the Wally World, but there is NO muzzle flash ever.  Bump Fire, whatever. In a range with NO lights or outdoors at night.

IMHO, Zero Flash is great for your eyes, better for your position security.

I will report back when I get my 14.5" back from having the Vortex pinned on. I expect no difference in results.

In a true "tactical" situation, IMO any flash would be to much. Many SWAT & millitary units are useing full surpressors now. As far as giving away you'r position, "tactical" to me implies relative closeness. Even my vortek has a signiture in total darkness and at close ranges the impulse noise from gun fire tends to give away you'r position fairly well.

i do a fair amount of shooting using many types of night vision, i have found Q3131A to have less flash than XM193 in both 20" and 16" pre ban barrels. the 20" has a phantom and the 16" has a A1 flash hider. SA battle pack has the lesat amount of flash of these 3 types. i once had some PMC in camoflage boxes that was the best.

funny thing about muzzle flash, it seems much worst when your up close to it but stand back 20 or 30 yards and its about half as bright. i was watching a friend fire his M4 barrel with a phantom from 25 yards away and the flash was not so bad. i guess if your in a night time fire fight the key would be to shoot and move.

as for flash huring NVD's, any scope worth having will have ABC(automatic brightness control) BSP(bright source protection). i see a slight flash in my raptor NV  scope even with a 20" barrel/phantom and using the SA ammo. pretty sure it will be OK. :)

South African battlepack & PMP ammo is definitly the way to go for flash suppression.. When I shoot in the dark with XM193, it can often blind me for about 3 seconds. I'd hate to deal with this in a fight.

my dissipator is notorious for being a "flamethrower" with xm193...puts out a fireball about 3 feet long and 1 foot in diameter in broad daylight (and this is Arizona daylight...its bright!).
i put on a post-ban legal CavComp from Cavalry Arms, and it redirects the flash a bit, but its still VERY pronounced.  
haven't actually shot any other ammo from it yet (been burning up all my good "rainy day" stuff), but i'm pretty sure its the ammo and not the rifle making it so bad...