Been trying to decide on a 308 semi auto in 16" configuration. Would the DSA 58 be a good option?

Its been a few years, but I recall reading that the FAL gas system did not lend itself to effective suppression.
 

FYI - you'll probably get better & faster answers in the NFA/Suppressor forum.

There's a lot of piston pop.  The same adjustable gas that moderates the recoil so well also vents a ton into the air under pressure.  You can avoid this by setting the gas plug to grenade mode, but then you have to manually cycle.

That being said, I'm going to can my FALs.  Still quieter than without it.  The one advantage the design provides is the ability to swap out the gas plug, which allows one to weld up the hole in the gas plug and redrill to a smaller diameter to reduce overgassing.  Changing out the gas plug is nearly as fast as adjusting the regulator, and more consistent.

There is a nice long thread detailing the FAL and suppressor use over on the FALFILES.

http://www.falfiles.com/forums/showthread.php?t=286840

Nice pictures and commentary.  It discusses the modification of the gas plug as a solution.  A good read.

I recently suppressed a 16" FAL (rifle length gas system). As noted above, an FAL is not the quietest setup, but if done correctly, it's lots of fun.

I did another approach to adjusting the gas for the suppressor. I wanted a similar quick adjust suppressor setting as is available on ARs, SCARs, etc., so modified the gas adjustment collar instead of the gas plug. Cut a steeper angle in the gas adjustment collar so that the full range of adjustment was ~120 degrees, attached a small adjustment lever to the collar so that it has range of travel throughout the entire adjustment range, and now can switch between suppressed and unsuppressed with a quick push of the lever using 1-2 fingers. Left enough adjustment on the reduced bypass end so that I can adjust for varying ammo pressure levels while shooting unsuppressed, and just push the lever all the way to the stop on the max bypass end for suppressed shooting. I still get more vigorous ejection with a suppressor (would have to drill out the barrel more for a larger bypass port if that was a problem), but the gas setting is still acceptable to me as is as I have no issue with blowback in my face even when shooting suppressed left handed. Prior to the mod, if I didn't open up the bypass enough I'd get almost sick from the amount of gas in my face from shooting suppressed, and wasn't able to comfortably shoot it suppressed left handed even when I did crank the bypass up.

Now this approach might result in a little more noise than a reduced port gas plug (not sure if to a noticeable amount, though), but I'm happy with how it works, and I don't have to keep track of an additional gas plug and have to change it out for suppressed shooting.

Slightly off topic, I've happily discovered no shift in POI between suppressed and unsuppressed shooting - that has not been the case with most of my other suppressed rifles. And I've gotten very surprising group sizes - smaller than I'd expect from an FAL. Probably little to no impact from the gas mods, though - I'm assuming it's more likely due to the shorter (16") barrel.

In full disclosure, it was actually a local gunsmith friend who performed the above mods for me (I miss having a garage with my tools set up in it). We'd discussed what I wanted and how I wanted it to work, and he made it happen. He's already repeated it for others who have seen my rifle and liked the approach.

It can be done.

I have mine fitted for the 7.62SD

The trick is to adjust gas. Take the gas port thing and mill it on the other side so that the grenade launcher side is the can side. Plug the regular port of gas that goes out the top of the relief cut in the front sight and slice and drill the other side so it doesn't chuck the brass to the next county. I cant recall off the top of my head the hole drilled.

Regular shooting on the normal side. Flip gas to other setting and it should toss brass to about the same distance as the other setting without having to adjust gas regulator spinning thing that is normally used.

 A bit of a thread necro but, you wouldn't happen to have a pic of said mod would you?

You can't drill both sides for different holes or you will be exposing the underside of the sight disk to high pressures it was not designed for.

I grind out the gas plug inlet hole and the C-cut and then reweld both and redrill the inlet hole to 5/64".  It is not a complicated mod.

Over on the FALfiles Stimpsonjcat was kind enough to weld and drill a spare gas plug for me. It works well and stops the bolt carrier from slamming into the recoil plate on the lower.