Original sentence: 25 caliber, and 6.5 mm diameters.30-30 case down to 7 mm (.30-30 case in the short 10 and 14 inch (25 and 35 cm) Contender barrels.30-30 wildcats in 6 mm,.30-30 will produce velocities of nearly 2000 f/s (610 m/s) out of the short 10 inch (25 cm) Contender barrel, though recoil and muzzle blast are strong from the short barrel.By allowing a more  efficient bullet shape, it allows a lighter bullet, higher muzzle velocity, and flatter trajectory
Edited sentence: 25 caliber, and 6.5 mm diameters.30-30 case down to 7 mm (.30-30 case in the short 10 and 14 inch (25 and 35 cm) Contender barrels.30-30 wildcats in 6 mm,.30-30 will produce velocities of nearly 2000 f/s (610 m/s) out of the short 10 inch (25 cm) Contender barrel, though recoil and muzzle blast are strong from the short barrel.By allowing a more efficient bullet shape, it allows a lighter bullet, higher muzzle velocity, and flatter trajectory