L4A6

[leeenfield]

I got my grubby little hands on a 1978 copy of the "illustrated parts catalogue" for the L4A4 and L4A6.

This seemed simple enough, but then I made the mistake of actually looking through it.

What is an L4A6? The body is a Mk3 pattern as is the L4A4...but:

The parts catalogue illustrates it with what appears to be an L4A1 hold open mag catch/ejector block, the rear sight is a different parts number from the L4A4, as is the barrel. In addition, this catalogue illustrations show the L4A6 body as not having the mag-well inserts.

[britplumber]

The A6 is the X10E1 or L4A1 re-issued with the MG5526 chrome lined barrel. Its the same progresion as A2 to A4 and the A3 to A5. I would imagine these to be very rare, but KG is bound to have one.

[Kev]

I wish I bloody had got one !
The only bits I've got are the magazine,ejector block and the slightly different shaped mag well cover
.......just thought it prudent incase one does turn up with a few bits missing ;D

I expect there's a forum lurker out there somewhere who has a minty one.If so start posting and show us some pics !

ATB Kevin

[leeenfield]

Mar 24, 2010 17:19:15 GMT 1 britplumber said:

The A6 is the X10E1 or L4A1 re-issued with the MG5526 chrome lined barrel. Its the same progresion as A2 to A4 and the A3 to A5. I would imagine these to be very rare, but KG is bound to have one.

So Mk3 Bren converted to trials 7.62 is A1, with chrome barrel becomes L4A6;

A Mk3 Bren converted to production 7.62 is A2, with chrome barrel becomes L4A4;

A MkII Bren converted to production 7.62 is A3, upgraded with chrome barrel becomes L4A5;

But why would the A6 and A4 have different rear sights and barrels? How many A1s did they convert to create a requirement for a newly produced chrome lined barrel.

If I understand the difference between an A1 and A2 it is that in order to accomodate the hold open device, the magazine has to be pushed forward past the .303 mag catch notch deeper into the receiver.
Does this result in a shorter barrel extention? Wouldn't that also result in different headspace than an A2?

[Kev]

1st bit -

Barrel assembly was the same for L4A6 and L4A4 - MG 20MA (From L4A6 CES,1961 and IPL L4A4 & L4A6 1963 & 1978 also EMER SA & MG E560-9

[Kev]

The HOD ejector block of the A1/A6 is 'roughly' the same size the A2/A4 ejector block from rear location to front face,so the magazine well shouldn't be any further forward between types.

[Kev]

CHS is the same for all L4 variants -
Also worth noting that the L4A1 barrel MG 92A is only 4 groove rifling and L4A2 barrel reverts back to 6 grooves but has a chrome chamber.

[leeenfield]

Mar 25, 2010 21:03:58 GMT 1 Kev said:

The HOD ejector block of the A1/A6 is 'roughly' the same size the A2/A4 ejector block from rear location to front face,so the magazine well shouldn't be any further forward between types.

Why does the locking nut spring recess break thru into the magazine locking lug recess then?

[leeenfield]

Mar 25, 2010 21:35:57 GMT 1 Kev said:

CHS is the same for all L4 variants -
Also worth noting that the L4A1 barrel MG 92A is only 4 groove rifling and L4A2 barrel reverts back to 6 grooves but has a chrome chamber.

Why no L4A3/A5 on the list?

Ugly sister?

[Kev]

Mar 25, 2010 22:53:34 GMT 1 leeenfield said:

Mar 25, 2010 21:03:58 GMT 1 Kev said:

The HOD ejector block of the A1/A6 is 'roughly' the same size the A2/A4 ejector block from rear location to front face,so the magazine well shouldn't be any further forward between types.

Why does the locking nut spring recess break thru into the magazine locking lug recess then?

Because that is where it has to go, both the FAL and Commonwealth locking lugs impeaded upon the spring recess.Also bear in mind that it was also supposed to be interchangeable with the L1A1.

The commonwealth locking lug on the magazine was stronger on the L4A2/4 and the problem of the barrel nut retainer spring breaking through was resolved with pinning it (4).



ATB Kevin

[leeenfield]

Thank you Kev, your collection of information blows me away; thank you for taking the time and sharing it.

I had thought that the L1A1 pattern mag used the Bren front locking "interface", just moving the ejector block latch forward. Obviously that is wrong

I guess I have to compare the 2 mags...

[britplumber]

All these problems stem from the 7.62mm round being rimless. The .303 round has a larger diameter due to the rim and therfor the 7.62 mag has to sit lower in the housing to allow the breech block feed horns to catch the round. This means the lip at the front of the mag also has to sit lower, and therefor cuts into the spring recess. This is also why the body inserts are used on the L4A2 etc. as most of the internal mag supports had been machined away to lower the mag.

I hope this also helps expain the reasoning behind the major mods involved in the 7.62 conversions.

[Kev]

Trying to find anything on the L4A3/5 is a nightmare.As most of the reference material has been gleaned by Tom over the years,if he hasn't found anything yet it's going to be a lucky day when something does turn up.

To illustrate the difference in the FN punched lip lug (L4A1/6) magazines and commonweath (L4A2/4) brazed on locking lug.



.....and yes the X3E1 mag is shorter

ATB Kevin

[britplumber]

Good photos Kev, I guess the diffrence in length is the diffrent springs?

The photo illustrates well the small FN type lug, its a bit teany weany by Bren standards.

Cheers, Chris.

[Kev]

Different type spring Chris, but I'm not sure they just made the mags a little bigger on the L4A1 type to ease the pressure ?



ATB Kevin