Though 8 inches in length my cock is only 6-1/4 in girth, so I'm not the greatest test to a deep throater. Nonetheless, I've only known two women who could deep throat me to the pubes (on their knees) or balls (in a 69) without uncomfortably forcing their way down and gagging. But I have encountered any number of men who could swallow it all with relative ease. A current suck buddy of mine initially had to force my cock into his throat (uncomfortable for both of us) to deep throat me and would often gag. Now he slips it down his throat quite effortlessly and seldom gags. So it's a talent that can be developed .... all it takes is practice, practice, practice. As for myself, I'm a large man with large head, mouth, throat, etc. and I've seldom encountered a cock I couldn't swallow all the way down with ease.