i just don't have good physical strength, i have handled military m16 it's like carrying a heavy furniture, there's just no way i can be good at it if self defense is needed, if i can get a 5lb instead of 6-7lb that could mean big jump in my ability to handle it, while the risk of malfunction maybe increased only marginally if at all. i searched the web extensively, although bushmaster/c-15 is generally not highly regarded, but i didn't see any real examples/incidences that owner reported it failed, and i guess thousands or even tens of thousands are out there and being used everyday, i did see one youtube video that it jammed, but author said poor quality ammo was used...