ACRTOME, welcome to the forums. As far as plastic lowers go, I used to feel the same way, about AR magazines. I was trained with metal magazines and by god I would have never touched them plastic toy magazines. That was my initial reaction when the pmags came out. I then began to better educate my self and began to see that the other guys were beating the living crap out of those "plastic" magazines and nothing seemed to face them. In the other hand my GI issued mags were breaking at the welds, warping, and getting dents all from just droping them 4 feet to the ground while conducting combat reloads on carbine classess. After I opened my mind and learned that the polymer used on modern firearm parts is stronger than aluminum I will never return to metal mags. Besides the ACR is already a pig when it comes to weight, to make an aluminum lower reliable it would have to be reinforced at certain areas increasing the weight even more.