Repairing Bren Mk 1 barrel

[Peter Laidler]

The good thing about foreign buyers buying L4's is that apart from the body, barrel and ejector, everything else they needed was on-the-shelf from their previous .303" gun days. Better still, barrels AND magazines were available far cheaper from Lithgow. So all-in-all, buying new L4's from the UK while part exchanging or trading in your worn-out Brens was a cheap option.. Alas, in late 60's and 70's post colonial Africa, they weren't as cheap as RPK's and RPD's...........

[Richard-]

Are the .303 and L4 7.62 firing pins the same, or similar enough to be interchangeable?

[Peter Laidler]

Identical - as is everything else. Or if it's not to the L4 spec, such as the bipod sleeve or, say, the butt or a Mk1 piston for example, it'll still fit and function

[Richard-]

Thanks Peter - I figured they would be - just noticed some opportunists selling 'L4' firing pins at a premium, so I was confused!

[Richard-]

I've had another go at drawing up a chamber repair, using an insert.

I've made the insert the same diameter as the chamber end of the barrel - 22.9mm

That doesn't give much wall thickness after the barrel is bored out though - only 2.9mm

I'd be interested to hear people's thoughts on this new drawing.

http://www.rarco.com.au/wp-content/u...9/20160925.pdf

[browningautorifle]

I might have made it a bit thinner and leave a bit more original barrel wall.

[Flying10uk]

Is there a reason why you don't have a stepped insert which you leave more of the original barrel wall?

[Peter Laidler]

DOOMED to fail - because the stability of the insert inside the original barrel relies on the surface area gripping it. And you have only got the insert held rigidly by half its length which equates to half of the circumferential area and sadly, half its adhesion. And it is the circumferential AREA for the full length of the insert that gives the insert its full adhesion inside the barrel.

That's just my opinion.

If you make it a full length chamber insert into the barrel you will still have the radial strength of the insert AND the radial strength of the part that seats inside the body........., the part that you have just chopped off! On the original barrel this part is a very close fit inside the body and it ain't goin' nowhere!

[Richard-]

Makes sense - thanks for your input.

That's why I like drawings, rather than a one line 'bore out the barrel and insert a chamber liner'.

Could mean lots of different things!

[Flying10uk]

Do you think the diameter of the insert which fits into the barrel/chamber ok, Peter, or would you recommend reducing it a little?