Complex sentence: The modifications included rechambering for bigger cartridge, modified recoil system, elevation controls were moved to the left side of the barrel where the sights resided, the elevation was limited, most of the guns received a muzzle brake.
Split into simpler sentences: The modifications included rechambering for a bigger cartridge, a modified recoil system, elevation controls that were moved to the left side of the barrel where the sights resided. Additionally the elevation was limited and most of the guns received a muzzle brake.