Barrett REC7

Gun Pundit has a nice picture up of the Barrett REC7, which is a piston driven 6.8 SPC AR.  That reminds me that I really need to think about a dedicated lower for my 6.8 upper.  Right now I use my Bushmaster lower if I feel like shooting 6.8.  Another note is that my 6.8 is direct impingement, and the upper seems to get dirtier more quickly than the 5.56.  The load difference between the two is about 4 grains of power, but I would imagine the amount of gas directed back toward the bolt carrier should be similar to 5.56, so I might just be crazy.  If I’m not, I think it’s worthwhile to have a gas piston setup over DI if you can afford it.