HAD MSF INSTALL A MID LENGTH PENCIL BARRE,A LINEAR COMP. .A GEN 3 SLIM HANDGUARD 12' AND I JUST SHOT IT FOR 1ST TIME HOURS AGO AND IT WAS SO PERFECTLY GASSED I WAS UNAWARE ALL MY EMPTIES LANDED IN A SMALL TIDY PILE ABOUT 4X4 FOOT SQUARE AFTER 40 ROUNDS. NEVER HAD THAT HAPPEN BEFORE. I'M USED TO MY BCA UPPERS SLINGING BRASS AROUND 2PM AT BEST. SO OVERGASSED THEY ARE AT BCA. LET ME SAY IT WAS ALMOST AS EASY ORDERING MY UPPER RECEIVER AS IT WAS SHOOTING IT. I'M A TERRIBLE SHOT SO 3 INCHES AT 100 YARDS WITH A 3X PRISM OPTIC HAS ME AS HAPPY AS CAN BE. DID I MENTION THE BALANCE IS SUPERB AND I COULD NOT BE HAPPIER AT THIS MOMENT IN TIME WITH MY LONG RESEARCHED PURCHASE. SO HAPPY THAT I ORDERED ANOTHER UPPER IN 7.62X39 WITH A MICROBEST BCG AND THE SAME RAIL BUT 15" LONG AND SLIM WHERE IT NEEDS TO BE. GOODBYE BCA. HELLO MID STATE FIREARMS!!!