im in the process of building a 11.5 ar pistol. but i cant find any concrete info on a question i have, im wanting to know if it is unlawful for me to put a magpul afg(angled fore grip) on this pistol. i have seen plenty of pics of ar pistols with them but do not know if it is lawful or not. i know it is unlawful to put a straight grip on any ar/ak pistol but do not know about the afg. any info would be greatful