When and why did the British adopt the 115gr bullet for the 9mm Mk1Z cartridge?
I know that Peter Labbett says the spec for the 9mm Mk1z ball was written in June 1941, and that initial production was at RL in '41 with the Blackpole production starting at the end of 1941. The only earlier 9mm procured by the British military (according to Labbett and the OB Procs I have) was a Tracer by Kynoch with a very light bullet (about 85grs I seem to recall). The original spec DD/L/11833 was written for the Sten, Lanchaster and S&W machine carbine according to Peter Labbett. This seems pretty straight forward until today.
I have two boxes of US made ammo with 115gr bullets, The first is a unique style Western box (pseudo-military) but the characteristics of the label would imply 1930s manufacture. The box code indicates the ammunition (Western hst) was loaded by Winchester (this was done as early as the 1930s). The date code on the box indicates the loading was done in 1935 or 1955. The second is a Winchester commercial box in the 1930 style, but with an overlabel identifying the bullets as 115gr. The code on this box indicates production in 1937 or 1947. The box styles would cause me to believe the 1930 dates, but who was using the 115gr bullet then---NO ONE THAT I KNOW OF!!! Neither of these boxes look like normal commercial production items, but rather something produced for a special order. (pictures of the boxes and discussion is on this thread: http://www.iaaforum.org/forum3/viewtopic.php?f=8&t=7737&p=54391#p54391)
I began to wonder if the British adopted the 115 gr bullet because of the rather delicate construction of the S&W machine carbine so I contacted a friend who is a S&W collector and on my behalf he contacted Roy Jinks who was the company historian and wrote the book on S&W aparently. Jinks looked in his material and told my friend that he had a document that said in 1939 the British provided S&W 10K rounds of 9mm for the development of the S&W Machine Carbine since the British ammo was more powerful than the US commercial ammo.
WHAT BRITISH 9MM AMMO IN 1939!!! The gun was tested almost two years before the British spec for the 9mm cartridge was even developed.
As far as I can tell, nobody was loading 115gr bullets before the UK started in 1941. The Italians began producing M38 steel jacketted ammunition in 1942 with an overall weight of 175gr-177gr which is consistent with a 115gr blt, but the 1941 steel jacket bullet in my collection weighs 190gr, consistent with a 124gr bullet. The 1938-1942 GM jacketted GFL ammunition I weighed was all 186-187gr consistent with a 124gr bullet.
It appears pretty clear that the British pioneered the 115gr bullet as a submachine gun load from everything I can find.
Three questions for the members:
Why did the British select a 115gr 9mm bullet in place of the well tried and proven 124gr bullet???
Is there any evidence anywhere (military or commercial) of British interest in a 115gr bullet before 1941????
How can we explain the apparent disconnect in timing between the British records and the S&W records? What was the ammo supplied to S&W by the Brits in 1939???
All info, opinions or thoughts are greatly appreciated.
Cheers,
Lew
I know that Peter Labbett says the spec for the 9mm Mk1z ball was written in June 1941, and that initial production was at RL in '41 with the Blackpole production starting at the end of 1941. The only earlier 9mm procured by the British military (according to Labbett and the OB Procs I have) was a Tracer by Kynoch with a very light bullet (about 85grs I seem to recall). The original spec DD/L/11833 was written for the Sten, Lanchaster and S&W machine carbine according to Peter Labbett. This seems pretty straight forward until today.
I have two boxes of US made ammo with 115gr bullets, The first is a unique style Western box (pseudo-military) but the characteristics of the label would imply 1930s manufacture. The box code indicates the ammunition (Western hst) was loaded by Winchester (this was done as early as the 1930s). The date code on the box indicates the loading was done in 1935 or 1955. The second is a Winchester commercial box in the 1930 style, but with an overlabel identifying the bullets as 115gr. The code on this box indicates production in 1937 or 1947. The box styles would cause me to believe the 1930 dates, but who was using the 115gr bullet then---NO ONE THAT I KNOW OF!!! Neither of these boxes look like normal commercial production items, but rather something produced for a special order. (pictures of the boxes and discussion is on this thread: http://www.iaaforum.org/forum3/viewtopic.php?f=8&t=7737&p=54391#p54391)
I began to wonder if the British adopted the 115 gr bullet because of the rather delicate construction of the S&W machine carbine so I contacted a friend who is a S&W collector and on my behalf he contacted Roy Jinks who was the company historian and wrote the book on S&W aparently. Jinks looked in his material and told my friend that he had a document that said in 1939 the British provided S&W 10K rounds of 9mm for the development of the S&W Machine Carbine since the British ammo was more powerful than the US commercial ammo.
WHAT BRITISH 9MM AMMO IN 1939!!! The gun was tested almost two years before the British spec for the 9mm cartridge was even developed.
As far as I can tell, nobody was loading 115gr bullets before the UK started in 1941. The Italians began producing M38 steel jacketted ammunition in 1942 with an overall weight of 175gr-177gr which is consistent with a 115gr blt, but the 1941 steel jacket bullet in my collection weighs 190gr, consistent with a 124gr bullet. The 1938-1942 GM jacketted GFL ammunition I weighed was all 186-187gr consistent with a 124gr bullet.
It appears pretty clear that the British pioneered the 115gr bullet as a submachine gun load from everything I can find.
Three questions for the members:
Why did the British select a 115gr 9mm bullet in place of the well tried and proven 124gr bullet???
Is there any evidence anywhere (military or commercial) of British interest in a 115gr bullet before 1941????
How can we explain the apparent disconnect in timing between the British records and the S&W records? What was the ammo supplied to S&W by the Brits in 1939???
All info, opinions or thoughts are greatly appreciated.
Cheers,
Lew