"That Guy" needs to do his homework. The gas and pressure builds up in a seal behind the bullet in the barrel LONG before it ever gets siphoned off into the gas system. Sauer of Kraut was ABSOLUTELY correct in initially looking for a 20" chrome-lined barrel with the tighter 1 in 7 twist. That may be hard to find, but that is EXACTLY what he needs for his terrain, choice of bullet weight, and for long-range shots with that platform. Maybe he has to go custom to find that combination, or maybe he goes FN/FAL or M1A. His call. I'm not an AR guy, but my dream AR would be a 20" barrel, chrome-lined, in 6.8 with a piston-driven system. While I'm dreaming, let me throw in titanium parts where need be. Hell - throw in ACOG optics also.