Re: SCAR vs ACR?
Have had both, just my observations... the acr's lower, seems like it's built a little on the cheap and might not stand up to much abuse. The safety loosely snaps together, the grip isn't replaceable and doesn't feel very solid. I did like the acr's non-recip charging handle and it's location is very handy. Could do without the flimsy barrel retaining setup. The enhanced fore end is pretty fat. The new version acr looks like an improvement, but I don't think it's commercially available, if it even exists? E Acr is on the heavy side and is front heavy.
Scar is a nice rifle. Lower is nicely engineered, made of quality polymer, seems tough (other than trigger guard), has a much better safety and you can replace the grip. Trigger is on the heavy side, with a good short reset though. Scar does have quite a few screws though, never had issues with any coming loose. Barrel is on the thin side, but still does ok when warmed up. Recoil feeling is less than the acr, regardless of muzzle brakes. Scar is lighter, very nicely balanced. Eotechs, mounts with quick detach levers or mounts with big nuts will interfere when manually operating the charging handle if its on the same side. Slight accuracy edge to the scar. Scar stock is slightly tighter locking and maybe a little tougher.
Add the acr's charging handle to a scar and you'd have a real winner, imo.... Beretta's new arx rifle, if ever available, looks like it will be better than both!