No5Mk1 being the rifles proper designation, is also well-known as the Jungle Carbine.
There were predecessors such as the No4 Mk1 Lightened, as well successors, such as the No5Mk2, Canadian Light rifles as well as an Australian version, the No6MkI and MkI/I. Unfortunately these rifles may total an entire production of 1500, where as the No5 Mk1 totaled around 250,000 alone.
The trials for this type of rifle started in the early summer of 1943. Is was becoming abundantly clear to the British Forces that a light weight rifle was required for jungle fighting with good accuracy of 400 yards. It was also later to be used by British parachute units in the 2nd World War, as it was the ideal sized rifle for that role.
During the early stages of the initial trials there was concern that the reduction in barrel length would result in a corresponding increase in muzzle flash. Fortunatly however the early trials showed the flash hider worked well and overall, the flash from the rifle was none the worse from that of a No4 being used in the same trial.
To offset the kick from the reduced weight of the rifle it was fitted with a rubberised butt plate. This along with its famous flash hider became somewhat the iconic pieces of the No5.
The No5 began production in 1944 and they were made either at the Royal Ordinance Factory in Fazakerley, Liverpool, or by the Birmingham Small Arms Company, Shirley. The easiest way to tell which one is to look at the left hand side of the receiver and see what is engraved there. If it looks along the lines of ROF (F) then Fazakerley, if it has M47C then the rifle was made by Birmingham Small Arms . Indication may also be on the wrist of the rifle.
The No5Mk1 was basically a shorter and lighter version of the No4. Besides the obvious differences , that being the shorter barrel length and a flash hider on the No5, there are a few other subtle differences that differentiated them. Yes the woodwork is different! but also the rear sight is only graduated to 800 Yds and the bolt is hollowed out in the bolt handle(however don’t get too hung up on bolts, nice to have matching numbers and a hollow, but it can still be the real deal with a solid handled bolt). But the key to spot a fake or bubba’d rifle is that the real deals have scalloped area where the barrel joins the receiver, there are others areas around the receiver that have been lightened, but remember that knox area! ( I will ask the owner of the rifle for permission to carefully remove the topwood for photos!).
Unfortunately the No5Mk1 had a reputation for not being able to hold its zero (suffering a term called a “Wandering Zero”). That is, the inability for the rifle after being sighted in and zeroed to a distance, to be able to be fired again some time later and achieving that same point of impact. Now this may be due to the lightening in and around the receiver, and it does make sence. I myself do not have one of these fine rifles yet, so can’t speak from experience.
The No5 Mk1 was produced from 1944 through to 1947 and total numbers were aprox 250,000. 2/3rds the production was from Fazakerley the other 1/3rd BSA Shirley. It was still a .303 calibre bolt-action rifle with a ten round magazine and weighed just over 7 pounds. The woodwork (furniture) was reduced as well and a rubberised butt plate was introduced, further reducing the overall weight . Due to the flash hider it required a special bayonet, oddly enough called the No5 Mk1 !. There were later version of the No5Mk1 rifle however these were in very limited numbers. These being the No5MkII and No6MkI.
Images with the kind permission of Paul.
Here are some further images of the No5.
Of interest note the reduction of wood in the stock, the fact the stock bolt was hollowed out as well. Also the amount of metal that was removed from the receiver area. You can almost appreciate the so-called wandering zero phenomenon. With more time I will properly label each image. Clicking on an image will bring it up to a larger size, using your arrows buttons left and right will scroll through the images, the ESC key will return you to the page.