.351 inch Winchester Self Loading
In the early part of WWI the French bought over 2,800 automatic rifles from Winchester, a mixture of about 2,000 Model 1907 in .351 inch calibre and about 850 Model 1910 in .401 inch calibre. These were to be used for arming aircraft before the successful introduction of machine guns.
It is known that the Royal Flying Corps held trials with the Model 1907 rifle in November 1915 and whilst there appears to be no record in British military archives relating to the Model 1907 rifle Winchester records show that Britain purchased 120 rifles and 78,000 rounds of ball ammunition on behalf of the RFC.
The Imperial War Museum has a M1907 rifle in their collection that is believed to be an ex-RFC rifle. It has been modified for Air service by increasing the size of the trigger guard and cocking piece to allow the use of heavy gloves and it has a fifteen round magazine instead of the usual ten.The serial number indicates manufacture in 1914. It also has evidence that a case catcher was attached at one time.
.351 inch Winchester M1907 rifle modified for Air Service (Courtesy IWM)
.351 inch Ball
The ball ammunition purchased from Winchester was their standard solid jacketed bullet so had nothing to distinguish it from normal commercial production.
The case was a straight sided semi-rimmed case. the headstamp was "WRA Co .351 S.L."
The bullet was round nosed with a cupro-nickel envelope and a lead core. Bullet weight was 180 grains
The propellant was about 20 grains of smokeless powder
Muzzle velocity was 1,400 fps
.351 inch Tracer
In his autobiography "The Other Mr. Churchill", the gunmaker Churchill refers to working in a shed on the War Office roof converting .351 inch ball rounds to Tracer by pulling the bullets, drilling the base and filling with tracer compound. One of these ignited causing him a serious eye injury.
This is the only reference known to Tracer rounds.
.351 inch Proof
When the Winchester Model 1907 rifles were purchased they would have been proofed by the military authorities on arrival in England in the normal way. A recently discovered packet of proof ammunition by Kynoch is circumstantial evidence of this, since it is unlikely there was much demand for civilian proof of these rifles in 1915.
The packet is dated 20 December 1915 and shows the proof charge to be 13 grains of Revolver Cordite. The packet is sealed but the rounds are likely to be identified by a purple stripe on the case head.
Right: Kynoch Proof round and headstamp.
Kynoch 1915 proof packet.
It appears that after the rifles were of use in aircraft they were passed to the Royal Navy as it is reported that when HMS Vindictive attacked the mole at Zeebrugge the bridge party had a rack of Winchester Model 1907 rifles as their armament.