Bren MkI gas system upgrades

[Lee Enfield]

If there were problems with the Bren MkI gas cylinder and gas usage, was there a program of upgrading the early cylinders with the later "improved" MkII and Mk3 gas cylinders during FTR or maintenance?

How serious a problem was it?

Information

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[Peter Laidler]

It eventually bvecame a MAJOR problem. During the war the actualk gas cylinder wasn't available as a replacement part. It wasn't the internal walls that wore out, but the external walls that were worn out by the constant swivelling of the bipod sleeve on the outer circumference that were always subject to a constant bombardment by hard carbon fouling the vented through the gas vents. The more it fired and vented (it actually ground itself away.....) the worse it got. Eventually a small arms instruction was issued that the area wasn't to be cleaned!

Post war, those Mk1 guns that were seviceable remained of course as did those deemed suitable for FTR and were upgraded with the Mk3 gas cylinder but the rest were DP'd or sold on.

The enigmatic Mk1 was not a happy gun and the worset offenders were the very earliest that we all yearn for now

[Peter Laidler]

I forgot to add that because the gas cylinders eventually (virtually) weld themselves in place, replacement was a Base Workshop repair and the attrition rate with scrapped bodies was about 20 percent.

[Brian Dick]

"Weld themselves in place". Ain't that the truth!! It scared the Hell out of me getting out an original from the 1940 date gun worth 30K here in the USA. Pics are on this forum. Red hot heat and brute frigging force was the key but scary nevertheless if it had galled.

[Peter Laidler]

As someone who has seen many destroyed, usually well worn and battered Mk3's and L4's, I salute your fortitude doing it. But I have a confession to make....... I didn't tell you that there was a chance that it'd all go pear shaped.

Sometimes you'd just strip the thread right out with the gas cylinder. Phew...., what an arse of a job!

[jmoore]

Why not bore the old one out until the tops of the threads on the receiver extention just start to show and then slowly pick out the remainder of the gas cylinder threads? That's how we often save expensive parts in the shop- It takes a bit of patience, but no force, or heat is required.

[Lee Enfield]

As someone who has seen many destroyed, usually well worn and battered Mk3's and L4's, I salute your fortitude doing it. But I have a confession to make....... I didn't tell you that there was a chance that it'd all go pear shaped.

Sometimes you'd just strip the thread right out with the gas cylinder. Phew...., what an arse of a job!

OK now that you've moved us off the MkI/I*/Im

What about a MkII to L4 conversion, keep the pressed and pinned gas cylinder or convert to threaded?

[Peter Laidler]

We never converted Mk2's to threadeed gas cylinder spec. Mind you, the Mk2 guns had their own gas problems. The gas cylinders worked loose. You could replace them once but if the taper pin hole had shaken oval then that was the end of the line for the gun

[Brian Dick]

I found out about the potential for galling when I removed two others, one a Mk.1 and the other a Mk.3 that I used to fix the gun from cut Bren receivers. The Mk.1 cylinder was destroyed. The Mk.3 cylinder lost about three threads off the end but cleaned up with plenty of thread left to spare. Fortunately, there is a God and the old original came out leaving the receiver female threads perfect. Whew.

I suppose the old one could have been bored out as you say jmoore but I was instructed the military way and that's exactly how I did it. It's just as well you didn't tell me the bad points too Peter. Luckily, it's not a job that needs doing often.

[jmoore]

Well,, whenever my little project gets underway it'll be first "heat and unscrew", but not TOO hard. If nothing gives after a hour or so of "gentle persuasion", it'll be time to break out the precision "destruct-o" tools.

Dang machinists- always cutting up..."stuff".