Using chem launcher with oxidizer or reinforcer then aiming and shooting with the Converted SMG-9 makes my recoil go straight down at a good rate rather than its normal recoil pattern going up. I specify those two because i havent unlocked the others. Tried other guns didnt get it to happen with them. Every time i do it with the SMG-9 however it repeats the downward recoil. Unfortunately i do not have a second SMG-9 currently to see if it happens with another.