L4A1 Development

[Peter Laidler]

South African 7.62mm and UK/Australian L4 Barrels would FIT but wouldn't interchange because the UK L4 series used ex Canadian 7.92mm locking shoulders and breech blocks while the SA guns used .303" breech blocks and locking shoulders.

[Lee Enfield]

South African 7.62mm and UK/Australian L4 Barrels would FIT but wouldn't interchange because the UK L4 series used ex Canadian 7.92mm locking shoulders and breech blocks while the SA guns used .303" breech blocks and locking shoulders.

OK, I understand that the 8mm and .303 breech blocks were different so that they couldn't be accidentally mixed up in service.

Why change the locking shoulders? What is the difference?

Can you fire 7.62mm in an 8mm Bren by simply changing the ejector assy and barrel?

[Peter Laidler]

Last question first.....
Getting a gun to chamber and fire another calibre is simple. The problem, especially with a machine gun is getting it to do the same thing automatically. This includes Fire - unlock, extract, eject, cock, feed, load lock and then fire again at 10 times per second.

So the answer is yes you COULD fire a 7.62mm round from a 7.92mm Bren by changing the barrel. It'd eject using the same ejector. But the real problem lies in the magazines/feed etc etc.

Why do the 7.92mm/7.62mm guns have different locking shoulders. You have answered your own question. The breech blocks are different because of the base rim diameter so cannot be interchangeable. So that a 7.92mm round can't be fired using a .303 breech block in a .......any way..... on and on..... they make the locking shoulders different so that even if you did interchange parts, the small difference in size will ensure that the breech block won't lift to lock, mechanical safety comes into play and the gun won't fire.

This is all pretty academic in the Commonwealth because we never used 7.92mm guns in the order of battle. But it soon became VERY important in the 60's when the .303" guns and 7.62mm L4's were in service, sometimes working alongside each other.

For the first 20 years of the L4's life, until the early 80's, there was always an oblong of red paint, approx 1" x 2" on each side of the L4, at the front of the magazine well that had painted on it in black 7.62mm. Having both .303" and 7.62mm guns in the same unit (we called it a mixed fleet) certainly kept you on your toes regarding spare breech blocks and locking shoulder sizes

[Kev G]

There is some info here regarding the SA conversion proccess.

KG

[Peter Laidler]

Just sent you a package KG.

[Kev G]

As the 7.62mm FN type magazine with it's FN locking lug needed to be further forward and deeper in the magazine well this led to the 'fragile' features.



The L4A2 and subsequent MK's (that used the body inserts) overcame the machining of the pocket nessassary for the FN locking lug that exposed the barrel nut retaining spring by the introduction of the 'commonwealth' locking lug on UK magazines
The very thin supports for the magazine lips was rectified with the magazine lip support body inserts that once fitted were machine profiled to the UK magazine lips and beefed up support for them.

KG

PS Cheers Peter :-)

[Peter Laidler]

The Commonwealth magazine lug A2 onwards L4's caused untold headaches at Enfield and even the drawings didn't appear to be correct. That was until in despair, they cut a Mk3 Bren body vertically in half from end to end. The answer was relatively simple.

The actual story of the L4 series conversion, which I call 'NATO standard please.....' in the forthcoming book is a great little story in itself and was interesting to rsearch because all the people/players were still alive and some of them were still well known to the Small Arms School plus we had mst of the documentation. A great gun.

Interestingly, the ex SA 7.62mm Brens on the UK dewat market amply show the real need for the strengthening inserts in the body

[Brit plumber]

I bet theres a number of old infantry men in Afghan who would give there I teeth for a L4 at the moment. I can't say I've seen much in the way of the L86 out there, I guess the Minimi is the LSW of choice.

[Peter Laidler]

You've got it in one Britplumb. We are now trialling a 7.62mm self loading rifle - just like the old L1A1 SLR and in the pipeline is a 7.62mm section LMG. Remind you of anything?

What goes around, comes around as they say

[Brit plumber]

Is that the new sharpshooter rifle? That looks a promising weapon, shame they havn't bought more of them!