http://www.valkyriearms.com/images/DeLisle_article.pdf
http://en.wikipedia.org/wiki/De_Lisle_carbine
http://www.militaryfactory.com/smallarm ... rms_id=686
http://historicalfirearms.tumblr.com/po ... e-designed

The weapon is an internally suppressed bolt action carbine in .45 ACP, which appears to use slightly modified Colt 1911 magazines. It was designed by a South African born (AndyC, you might find this interesting) and British educated engineer by the name of De Lisle for British intelligence. Much of De Lisle's life and this gun's history is still hidden by Britain's Official Secrets Act, but thanks to a small-arms scholar by the name of Ian Skennerton who actually knew De Lisle, we know some things about both the man and his design.
The carbine design started life as a home-built suppressor De Lisle built for himself as a teenager. Later, when rationing made meat scarce, De Lisle used his can mounted to a .22 to put meat on the table during the war. He was approached by the British government to design an upscaled version of his .22, to be chambered in 9x19mm, which had become the standard British sidearm cartridge at the time. But De Lisle himself suggested that .45 ACP would be an even better application of the design, for the reasons of being both subsonic and better terminal ballistics. When the 9mm variant development proved problematic, De Lisle scrapped it. He then built the .45 caliber version, using the S.M.L.E. Enfield action as the base platform, to which a Thompson SMG barrel, cut to 8.5" was attached. The barrel was ported with 24 holes in 4 sets of 6 holes each, and then the suppressor was mounted, enclosing the barrel entirely. In testing, it proved to be more quiet than a Crossman pellet pistol.
The carbine was initially issued to and used by British commando forces during WW2, and used later by SAS for COIN and counter-terrorism, and saw combat use as recently as the Falklands war and against the PIRA in Ireland. It's primary use was for taking out sentries during raids. Relatively few of these were built by the British during WW2 (a little over 100 of them being publicly acknowledged), all being for spec ops purposes and built outside the normal British supply train. After the war, other countries also built them, in larger numbers. The thing is, the Commonwealth nations won't even admit to building them at all or to their existence, as they are covered by the Official Secrets Act, so we don't really know how many were ultimately built. But, they did show up in Israel in 1948 and in Malaya in the 1950s, for instance, so somebody was getting their hands on them, and between those distributions it appears that the brits manufactured many more than they acknowledge. Clones were manufactured, for the same purposes, by other governments, such as France, South Africa, and others.
The more I read through the PDF linked above, the more I thought about how cool it would be to have a short-barreled, accurate, bolt action, suppressed carbine in a pistol caliber..........then I thought immediately of the .300 blackout cartridge and the modern variants of bolt-action short-barreled rifles built on that caliber. Very cool guns indeed. But still, wouldn't it be a neat variation on the idea of having similarly chambered long guns and pistols, to include an internally suppressed bolt gun in .45 ACP alongside a 1911 pistol?
I hope you all enjoyed learning about this gun as much as I did.