(The material for this post came primarily from a post made by Roger V. Lucy at the MilArt blog, which also has information on a couple other WWII Canadian experimental projects)
When we see rifles, typically No4 Lee Enfield rifles, marked with the name “Long Branch“, we are actually seeing the production of Small Arms Ltd. (SAL), the government-owned company which encompassed the Long Branch arsenal outside of Toronto, Canada. The arsenal is best known for its productions of rifles, but among other projects it also experimented with a series of self-loading rifle designs during World War II. None of them made it into series production, but they are interesting to see.
The 1944 SLR
These experiments began late in the war; April 1944 was when SAL started work on the first of the line. The British government was apparently interested in a self-loading rifle chambered for the 8mm Mauser cartridge (note that they were using the Czech vz37 machine gun, aka Besa, in 8mm). In response, SAL designed a rifle with a tilting bolt action along the lines of a Bren. It was ready for trials in June of 1944 – a very impressive (or perhaps hopelessly rushed) development time of just 3 months. I have no details of the trials, except a suggestion that the gun was either too heavy or had sacrificed reliability in pursuit of a lighter weight.
Action: Tilting bolt
Length: 45 inches (115 cm)
Magazine capacity: 10 or 20 rounds
Bayonet: British standard No.5
The 1945 SLR (EX-1)
After the rejection of the 1944 model of rifle and a nearly year-long delay, the rifle was redesigned in March of 1945, with this second model ready for trials in May 1945 (another remarkable 3-month development period). This model used a bolt with locking lugs at the front (as opposed to the Bren-style with a locking surface at the rear of the bolt) and apparently was significantly lightened as a result – but was also deemed overly complex and fragile when tested in August 1945. Improvements were made, and by December of 1945 the test rifle had run 800 rounds successfully.
At this point, the Canadian military began to express interest in the rifle, and the Director of Artillery pushed for further funding of the project. Continuing work reduced the rifle’s weight from 10 pounds to 9 (4.5 to 4 kg) and simplified its mechanism. Another trial prototype was scheduled to be ready for testing in April of 1946, but at this point the program began to be overtaken by the competition elsewhere to develop self-loading rifles.
The 1946 SLR (EX-2)
The Long Branch Arsenal and Small Arms Ltd. were dramatically reduced in size shortly after the war ended, and this would have led to the end of theSLR development program. It was decided to continue the work through Canadian Arsenals Ltd., which had taken over operation of the operations at Long Branch. The goal was to rechamber the rifle for the T65 cartridge being pushed by the US, and reduce the rifle’s weight to just 7 pounds (3.2kg). A select-fire option was also to be investigated. This would have conformed to the general NATO rifle program, which would focus on the EM-2, T44 (M14), and T48/FAL rifles.
Ultimately the Canadian rifle experiments here would be overtaken by the FN-FAL and would not see any production beyond the prototype stage. Unfortunately, I do not have any more detailed information on the internals of the various iterations, nor on their trials results.