§ MR. COURTHOPE (Sussex, Rye)To ask the Secretary of State for War what breech pressure is exerted by the .303 ammunition producing a muzzle velocity of 2,600 foot seconds with a 1322 bullet of 150 grains; and what are the length in calibre of the point of the bullet, the point-blank range, the ballistic coefficient, the time of flight for 1,000 yards, and the deflection at 1,000 yards for a wind of ten miles per hour.
(Answered by Mr. Secretary Haldane.) As regards breech pressure, a mean pressure not exceeding 18¼ tons would be exerted. No pattern of 150-grain bullet has yet been decided upon, and it is not therefore practicable to give any information as regards the length in calibre of the point of the bullet or the ballistic coefficient. As regards point-blank range, the range in which a 150-grain bullet, at 2,600 f.s. velocity, would not rise more than five feet above the line of sight would be about 700 yards. The time of flight for 1,000 yards would be about two seconds (calculated), but this varies with different designs. The deflection at 1,000 yards for a wind of ten miles per hour would be about 12½ feet (calculated).
§ Mr. COURTHOPETo ask the Secretary of State for War what are the point-blank range, the breech pressure, the ballistic coefficient, the time of flight for 1,000 yards, and the deflection at 1,000 yards for a wind of ten miles per hour, in the case of each of the following types of .303 ammunition: service Lee-Metford, with bullet of 215 grains; Swift, with bullet of 225 grains; Velopex, with bullet of 150 grains, and Lee-Metford Palma, with bullet of 225 grains.
(Answered by Mr. Secretary Haldane.) For the service 215-grain bullet the point-blank range for a height of trajectory above line of sight not exceeding five feet is 550 yards; as regards breech pressure the mean pressure does not exceed 16½ tons. The ballistic coefficient is .42 approximately; the time of flight for 1,000 yards is 2.4 seconds; the deflection at 1,000 yards for a wind of ton miles an hour is 13¼ feet (calculated). Similar information as regards the three other bullets is not available.