The Lee Enfield No. 5 MK1 jungle carbine

With ANZAC day tomorrow, this Firearm Friday, it seemed appropriate to focus on a military rifle. There is almost too much information about this rifle. The Lee Enfield No. 5 MK1 jungle carbine is the frankenstein's monster of the Enfield 303.

The SMLE, Rifle No 4, was a terrific rifle but very heavy – great for standing up to the knocks and rigours of a battlefield, as well as absorbing recoil, not great for carting on a hunting trip through the bush for a great length of time. Civilians solved that problem by sporterising the rifles — cutting down the woodwork to reduce the weight and make the rifle easier to handle. However, the military needed something a bit less makeshift and began developing an official carbine version of the No 4, which had been adopted as the standard British service rifle in November 1939.

Development of a shorter and lighter rifle for use in the Far East theatre was under serious consideration by June 1943, and by December that year, the Royal Ordnance Factory at Fazakerley, UK, had been asked to produce 1000 carbine versions of the No 4 Mk I for trials and testing purposes. By 21 March 1944, most of the quirks had been ironed out, and Fazakerley began full-scale production of the new carbine rifles, officially designed Rifle, No 5 Mk I, joined later by BSA from its factory at Shirley.

Jungle Carbine is a nickname that has become the universal name for the Lee-Enfield No 5 Mk 1 and is not the name it was given at manufacture. It was never used in official documentation or reports while the rifle was being developed.

They made several changes to reduce weight and make the rifle more effective in jungle and bush situations. The most obvious is the shortened woodwork, similar to that found on sporterised SMLE and No 4 Lee-Enfields, along with the flash-hider on the barrel, and a buttstock with the sling attachment on the side, rather than the bottom.

These changes give the rifle its distinct and instantly recognisable appearance, the flash-hider in particular being particularly distinctive. The rear sights are only graduated to 800 yards instead of the 1300 yards on a No 4 Mk I; most Jungle Carbine sights have a micrometer-adjustable range setting.

Working on the theory that “ounces turn into pounds” (as it was in those days), the bolt-handle has been hollowed out, and scallops of metal have been removed from the area where the barrel connects to the action, as well as the rear of the action behind the charger bridge. The buttstock also has a large cavity in it as a weight-saving exercise.

As a result of the shorter length and weight-saving features, the No 5 Mk I weighs 3.2kg, comparing favourably with the 4.1kg of the No 4 Mk I.

A grenade-launching attachment was also developed for the rifle, but it does not appear to have seen much use. At least 170,807 Jungle Carbine rifles were produced by ROF Fazakerley, while BSA’s Shirley factory produced 81,329. The rifle pictured in this post is from the Fazakerley Factory.

Production ended in December 1947, partly over concerns about accuracy and zeroing issues with the rifles.

While the Jungle Carbine was designed during WWII, and first went into production in late 1944, there’s little evidence the rifles actually made it to the Far East theatre, despite them being designed for use there.

They were first known to have been used by British 1st Airborne Division forces occupying Norway after the German surrender in May 1945. The British troops had been issued with the rifles due their obvious usefulness for airborne troops, and while a fight was expected, the German soldiers occupying Norway surrendered peacefully.

Most No 5 Mk I rifles were sent ‘East of Suez’, seeing plenty of front-line use in the Indonesian National Revolution (1945-1949), the Malayan Emergency (1948-1960), the Korean War, and the Mau Mau Uprising in Kenya (1952-1960). As with the various other .303 designs, many continued to pop up in various conflicts throughout the remainder of the 20th Century.

Debate about the wandering zero has been raging in the military rifle collecting community for decades, and the current understanding seems to be that a small number of the rifles were affected by the problem, likely caused by manufacturing issues and the flex caused by the lightening cuts made to the action.

This is further confirmed by reports from British and Commonwealth armourers in Malaya in the late 1940s and 1950s, who found that replacing the Jungle Carbine action with a regular No 4 action solved (or mitigated) most of the issue.

The British Ministry of Defence did look into the wandering zero issue just after WWII and again in the early 1950s and conceded there might be something to the complaints, but with a semi-automatic rifle inevitably about to become the military’s standard-issue rifle, it wasn’t considered worth thoroughly investigating or trying to fix it — beyond discontinuing the Jungle Carbine in December 1947 and switching production back to the Rifle No 4.

The Jungle Carbine had an aperture sight for most shooting, and a micrometer-type flip-up sight for up to 800 yards, which was rather optimistic in accuracy

Very few of the Jungle Carbines still around today have been reported to have the wandering zero issue, and it’s quite likely the issue (and the number of rifles affected) was played up somewhat to hasten the introduction of a semi-auto rifle by the British military.

The Jungle Carbine uses the same action as the Lee-Enfield Rifle No 4 Mk I and features the same 10-round magazine.

The ghost-ring battle sights work well for quick target acquisition at closer ranges, while the flip-up sights allow for longer ranges, although realistically, you’re unlikely to be firing a Jungle Carbine with iron sights much beyond 300m, which is the battle-sight range.

The unusual butt pad probably worked well, but these days the rubber has hardened. Recoil, at least in my experience, is on par with the regular Lee-Enfield; by modern standards, even the Jungle Carbine has some weight to it, which helps absorb recoil. The unusual rubber butt plate fits well into the shoulder, but doesn’t really absorb recoil. Apparently, it had some beneficial effect back when the rifles were first made, but age has hardened the rubber.

Accuracy-wise, at regular hunting distances, the rifles perform as well as the No 4 rifles they are based on. While the sights are graduated to 800 yards, no one is trying to shoot a Jungle Carbine that far and even if they were, they wouldn’t seriously expect much in the way of accuracy anyway because of the distance.

Whether you’re looking for a military surplus rifle ideal for bush and scrub hunting, looking for something different for Service Rifle competitions, or are a collector looking for an important piece of Lee-Enfield history, the Rifle No 5 Mk I Jungle Carbine ticks a lot of boxes and remains one of the most sought-after Lee-Enfield rifles more than 75 years after production ended.

I took most of the information for this piece from Royce Wilson's article in Sporting Shooter.

SPECIFICATIONs

Calibre: .303 British

Action: Bolt

Magazine: 10 round magazine, charger loaded

Barrel Length: 50.8cm (20.5in)

Overall length: 100.3cm (39.5in)

Weight: 3.2kg (7lb 1oz)