disclaimer. this will be my first privately owned KAC anything.
i have a 10.5 inch barrel with an a2fsb on it. what is the longest urx3 i can use and still keep the fsb? i was thinking of the 8 inch rail but i dont know if it will be too long.
ive seen some of the carbine length urx rifles and it looks like there is a small gap of about 1/4 inch in between the end of the rail and the fsb.
thanks for the input