I got a 16" fal carbine from orf.blast doesnt seem a big issue,it shoots just fine.Id let you shoot it nightcrawler if you were here in ohio.theres nothing fancy about it.
Im not overly concerned with loss of velocity and all that jazz, its a battle rifle,no fancy barrel,no optics,just plain ol post and I shoot it at ranges in the 100 yard window anyways..I would consider an bolt action with optics that I can squeeze maximum accuracy out of to need the longer barrel, but for a fal,what it does, it does it well.