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There were difficulties with the early Kynoch ammunition and British made BESA barrels as the 1937 ammunition had a fatter ogive to the bullet than Czech ammo and gave excessive fouling in the leed. Consequently the first mark of ball ammunition adopted had the slimmer ogive of the Czech bullet.
Ball Mark Iz
Cartridge S.A. Ball 7.92mm Mark Iz" was approved to DD/L/9242 in May 1939 and shown in LoC Paragraph B.3311 dated March 1940. It was only manufactured by Kynoch.
The case was Berdan primed and the cap held 0.5 grains of cap composition. The cap was ringed in and had a purple annulus. The headstamp included the numeral "IZ"
The boat tailed bullet had either a GMCS or CNCS envelope and a lead antimony core. It weighed 198 grains and had one cannelure. The ogive radius was 2.94 with a length of radius of .866 inch, which matched the original Czech bullet.
Propellant was 45 grains of nitrocellulose.
Left to Right: PCH 40, P C 40 IZ, K39 IZ.
Greek Ball Mark Iz
In addition to British made Ball Mark Iz, supplies were also purchased for the the Greek Powder Company (Pouderie et Cartoucherie Hellenique) in 1940, having been tested by CIA in 1939 and found to be of good quality for the Besa gun. At least 170 million rounds were ordered under Contract 294/C/6271. The bullet weighed 198 grains.
Early deliveries were headstamped "P C H 40" but later rounds were headstamped "PC 40 IZ".
The label illustrated below is for non standard ammunition since it is printed in black on white paper. It may be for the Greek Ball Mark Iz or for the "K37" pre Mark I ball round.
Outer label for case of 7.92mm Ball. Note that no Mark number is shown.
The Ball Mark Iz proved to be inaccurate in guns with worn barrels and so trials were held once more with bullets with a fatter ogive. These proved successful and so a new mark of ball was approved with the "K.37" ogive.
Ball Mark IIz
Cartridge S.A. Ball 7.92mm Mark IIz" was approved to DD/L/12603 in September 1941 and shown in LoC Paragraph B.7986 dated
July 1943.
The case was Berdan primed and the cap held 0.5 grains of cap composition. The cap was ringed in and had a purple annulus. The headstamp included the numeral "IIZ" or after 1945 "2Z".
The boat tailed bullet had either a GMCS or CNCS envelope and a lead antimony core. It weighed 198 grains and had one cannelure. The ogive radius was 2.26 with a length of radius of .866 inch. The length of boat tail was also slightly longer than the Mark I bullet.
Propellant was 45 grains of nitrocellulose.
Muzzle velocity was 2,480 fps at 90 feet at a pressure of 21 tsi maximum.
Ball Mark 3Z
In 1949 trials were held again to test flat based bullets in an effort to increas accuracy and reduce barrel wear in the 7.92mm BESA gun. These trials were relatively successful and although the Ordnance board recommended that future BESA ball should be flat based no further action was taken and the BESA was phased out of service There is little doubt that had the bESA continued in service thsi bullet would have become the Ball Mark 3z. Bullet weight was 150 grains.
left: Potential Ball Mark 3z
Ball, American manufacture
In 1942 consideration was given to using a flat based bullet in both the 7.92 and 15mm BESA guns as that would allow the use of Cordite propellant which was much more suitable for use in India and the far East. There was about 50 million rounds of American made 7.92mm ball available loaded with flat based bullets and so a trial was arranged to test the compatibility of this ammunition with British made. It was found that they matched at ranges up to 500 yards,but while divergence grew after that it was not considered unacceptable and so American ammunition was recommended for service.
Ball ammunition made by both Winchester Repeating Arms Co. and Western Cartridge Co. was imported, the former with the headstamp "WRA Co. 8M/M" and the latter with "WCC 42 8M/M".
Post war further trials were held with flat based bullets to improve accuracy in the worn barrels of tank guns when firing overhead in support of assaulting troops. The bullet was designed by Kynoch and based on the old German "S" bullet, weighing 154 grains without cannelure. The design was BK 101/31A and was successful, reducing barrel wear and improving accuracy.
Had not the 7.92mm become obsolete, it is likely that this bullet would have become the Ball Mark 3z.
Unheadstamped Ball
In 1964-65 Kynoch manufactured 4 million rounds of unheadstamped ball ammunition with 154 grain flat based bullets for the British government. This was delivered either to the Crown Agents for Aden or to British ordnance depots.
Left: Packet label for unheadstamped Kynoch ball.
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