I printed the double rib Hoffman ar15 lower (Polymaker PLA plus) and mated it with BCA .22 LR upper. Shot about 5 rounds through it. I stopped because it started to smell like burning plastic. Is that normal for the first few shots? Also, the .22 LR magazine is really loose in the magewell. Even fell out after one of the shots. Has anyone had this problem? Maybe I didn't screw the mag release button tight enough? Everything else seems to fit and move right. Thanks.
