Service lines and projectiles.
Service projectile lines hereafter approved shall be similar in size to that used by the United States Coast Guard, of not less than 1,700 feet in length, and capable of withstanding a breaking strain of 500 pounds, and the projectile end shall be so protected that line will not burn when fired from the gun.
The projectiles required to be furnished with each gun shall weigh not less than 18 pounds, smoothly turned and finished, with a windage of not more than one sixty-fourth of an inch.