1907 headspace change, does anyone know why?

[ireload2]

1907 headspace change, does anyone know why?

Doesn't anyone have any reference material relating to this?

The headspace for the Enfield Rifle was changed in 1907 does anyone know why i.e. Boer War findings from field use, improvements in cartridge case design etc????????

"Gauge, Armourers - Jul 9 1907, Distance of bolt from end of chamber, .074 inch.
All magazine rifles and carbine; rejecting gauge

Approval having been given to increase the rejecting limit of the distance between the face of the bolt-head and end of chamber of magazine arms in the hands of troops by .002-inch, a pattern of the above-mentioned gauge has been approved.

Officers commanding units and Ordnance officers in charge of depots, with an armourer attached, and Ordnance officers in possession of the reference gauges referred to in Appendix IV of the Equipment Regulations, Part I, 1906, will demand gauges of the new pattern and return the .072 gauge to store.

For Naval Service the rejecting limit will be as follows for rifles under examination and repair at Naval Ordnance depots ...................072 inch for rifles on board ships, &c.............074 inch

Supply of the gauges to ships &c., will be arranged by the Admiralty."

Tracking this change backwards gets original .303 headspace very close to current US SAAMI standards doesn't it? I have always suspected that current SAAMI specs are closer to the original dimensions than are current British standards.
Why? The .303 British was never a US military cartridge subjected to the British engineering changes. However it was a US commercial round subject to US industry standardization. Just because the British military needed to change did not mean there was any reason to change US commercial manufacturing practice.