ar-15 weird noise

i have a ar-15 cmmg brand just purchased a day ago never fired that has a ratteling noise as if something is loose inside the stock when the rifle is field striped and the lower is tilted front to back normal? should i return? the only reason i ask is one iam a noob to cmmg and second i bought the gun online from cheaper than dirt and its a pain to sen it back with the ffl and all

It’s the tungsten weights in the buffer, Cleatus. Perfectly normal.

thank you sir very appriciated