The .30-06 (7.62x63):

During the second world war the British army had a shortage of machine guns (M.G.'s) for the armoured vehicles and airplanes. This problem was solved by purchasing Browning machine guns from the United States of America. these M.G'.s were in the caliber .30-06. There were also rifles and machineguns in .30-06 purchased for the British Home Guard.

At that time the U.K. did not produce .30-06 cartridges by itself so they had to buy the cartridge together with the Browning M.G.'s. A little time later the U.K. started to produce their own .30-06 cartridges. The British .30-06 was produced in several variations and was used until the late sixties.

The cartridges used by the British army:

Below is a selection of  .30-06 images shown. all these cartridges were approved for service in the British army. 

Ball:

   British .30-06 ball.

Ballistic Standard round:

The ballistic standard round can be identified by the yellow primer annulus.

Tracer rounds:

The first tracer rounds were bought in the U.S. (special contract and with normal military headstamps)  Later the tracer round was produced in the U.K. 

from left to right: US tracer, 2x british tracer, HS: K 53 

AP rounds:

The AP rounds were mostly purchased from the U.S.A.

American M2-AP round (With DEN 43 headstamp)

.30-06 Blank cartridges:

Drill rounds:

Several drill rounds, including one produced by Parker, U.S made and British versions.

Proof rounds:

Proof rounds are copperwashed for identification. Sometimes an extra purple line is painted  on the head of the case(see image)