For .223 Remington 55gr FMJBT, the Sierra Manual says at an OAL of 2.250 it will take 25.7 grains of Hodgdon H335 to produce 3000 fps. The Hornady Manual says at an OAL of 2.200 it will take 22.4 grains of Hodgdon H335 to produce 3000 fps. Does the difference of .050 really increase the pressure that much to achieve the same 3000 fps with less powder? If so, why wouldn't everyone use the shorter OAL and save on powder? Also, at what grain increments do I work up my loads? Do I go by what the manual says and increase according to fps (load data is usually shown in 100 fps increments)? Or do I just increase my loads by a certain amount of powder?