Complex sentence: Nominal bullet diameter is 0.257 in (6.53 mm) and bullet weights range from 75 to 122 grains (4.9 to 7.9 g).
Split into simpler sentences: Nominal bullet diameter is 0.257 in (6.53 mm). Bullet weights range from 75 to 122 grains (4.9 to 7.9 g).