During the start of the camp rescue scene, Schoolboy is seen to be using a suppressed 7.62mm sniper rifle, yet later on as Rambo and Sara escape the camp, Schoolboy's rifle changes to a M98 with a muzzle brake. While it IS plausible that Schoolboy COULD take 2 rifles into the jungle with him and ditch the smaller rifle for the M98, it would be highly improbable.