the F FSB is a valid concern but easily remedied by the taller pin (which delton also sells)
but its not anything to sway you away from Delton. many commercial AR's ( Bushy, Del-ton,olympic, stag, SW, DPMS etc) dont use the F base
but its not anything to sway you away from Delton. many commercial AR's ( Bushy, Del-ton,olympic, stag, SW, DPMS etc) dont use the F base