That pic is over 15 years old, sold them ten years ago due to a nasty shoulder injury that wont take the reciol. Bach in the day though the Barrets where king of fun with the 82a1 being king and the 99 not far behind. The Subos where not bad to shoot but the AR50 and States tended to be the most accurate just behind a Mcmillion.
Someone also made an Ar upper the bolt screwed into that was very reasonable? A google search might be in order as like I said my info is over ten years old but I can tell ya we burned up all the cheap ww2 ammo that was left years ago.
Another good tip is to find someone still in the game. Around here a visit to the annual cannon shoot would give you a lot of insight