There is moderate flash from Lithuanian M80 ball I have tried. If full flash suppression is required another device like a Smith Enterprises or AAC is needed, or a can of course.
I ended up with an AAC Brakeout. The carbine's recoil is soft, but I wanted to cut back on the muzzle jumping. The Brakeout took care of that handily as well as cutting recoil down towards 5.56 levels. Flash with the Brakeout is similar to the factory A2 unit.
BTW my MWS has the 16" chrome lined barrel and is a very honest sub minute shooter with Federal 168 gr. GMM or my equivalent hand load using IMR 4895. No flash signature testing to report with these sort of loads, but they were darn good back when I shot M1As, so no concern. But then again, I don't hunt bad guys or pigs, just curious.