am told this is a "DPMS pattern gun"so am asking if some stuff fits. magpul BAD does not. looking for an ambi/extended charging handle. the radian brand raptor looks like what i want. does anyone know if this fits/works. can't seem to contact radian. as far as mags go,most of what i see recommended is magpul which is fine. wondering if any one has input or experience with promag or dpms steel or any other steel that memebers might know about. i am aware of some problems with dpms and promag is not really a first line company,but i do like steel mags and do have some magpulsas well so just asking. thanks for replies.