Slight newb thread detour: if you were to get a slick side upper and encountered a bolt issue, what are your options? I've been learning as much as I can about ARs in the last couple weeks on my way toward a build and the forward assist issue seems ambiguous -- most people never use it, but you'd "need" one to clear a bolt malfunction. I guess I'm unsure what kind of malfunction that would be, if jams can be cleared by working the charging handle.
I don't think I've really heard of any typical malfunction where you're required to use the FA.... it's more just an institutional inertia thing, like hitting the FA after you've loaded your rifle and sent the bolt into battery.
FTF - Tap, rack, bang.. unless you follow the traditional SPORTS (Slap, Pull, Observe, Release, Tap <- Tapping the FA here, Shoot
Stove Pipe - Either sweep away the brass, or Tap, Rack, Bang it
Double Feed - Lock the bolt to the rear, eject the mag, rack the charging handle, feed it and shoot
Bolt Override or Charging handle impignment (kinda rare) - strip the mag, and pull the bolt bag with your finger (either from the ejection port or mag well), the rounds should fall out, then feed it and shoot
You DO however need to use the FA to help put the bolt back into battery, after doing an improper press check, or if it's REALLY dirty inside, sometimes, the bolt won't go back into battery properly, but then you just need to strip it down, clean it and lube it, since we're just at the range we can do this, we're not in some FOB under fire by 10,000 guys with RPGs and AKs. But if you have a clean well maintained gun, then you shouldn't have to use it...