I guess you could I switched to mill spec lower and pws buffer tube and geissle trigger in mine. My friend that has two of the huldra piston uppers in the 556 with the lw15 lowers did just that he switched all the plastic lpk with metal and is over 600rds without a problem. And my buddies dad that has one of my lw15 lowers hasn't had any problems with it on a rra upper 556 upper. Guess I just had bad luck but I would at least switch the fire control group.