Inglis 7.92mm Bren

[Kev G]

As a matter of interest regarding the 7.92 'sterile' Brens marked - 7.92 BREN MKI and the difference in the piston and piston extension between these and all other types of .303 and 7.92 (CH & 0T prefix) Brens some further info.

As mentioned earlier the piston location pin is further forward on the 'sterile' 7.92's on the very few that I have seen.



As there may have been some doubt on this feature on these few guns I thought it prudent to check with the examples (accession number 19760332-092, serial number 1-0001 and accession number 19760332-054, serial number 2-3429) held by the Canadian War Museum.
These were aquired by the CWM straight from Canadian Arsenals Limited so there provenance should be good.

Both Brens have been inspected and they do indeed have the same piston and piston extension as per other 'sterile' 7.92 Brens with the piston location pin further forward.

As the pistons and extensions are not threaded in these guns the location pin has to be further forward to mechinicaly join them.The location pin on all other types being at the bottom of the piston thread to arrest the possibility of the assembly becoming unscrewed.



Apart from this being possibly the only item that could be simplified in the process of Bren production it would also require a smaller in length and larger diameter location pin.

As no other Inglis Brens have this feature would it indicate these were the last Brens produced there ?

Inglis were not allowed even the slightest variation from the drawing spec without specific Enfield/Ministry of Supply approval, even for the boxes, fittings and ancilliaries ets etc

Is there any known record of this modification/alteration Peter and if so is it dated ?

If the serial numbers on these guns are not random but run consecutivly in batch numbers of 9,999 is there room for 18,000 odd guns in between the known 0T and CH serial 7.92 guns in total WW2 production figures of 7.92's ?

As they don't have any inspection or acceptance marks on them would they count anyway ?

Appologies for so many questions but any thoughts , observations or further info much appreciated.

ATB Kevin

[Peter Laidler]

I read exactly what you say about the possibility that the 'mystery' 7.92mm Brens have a differently configured piston and piston interface connection. But a bit of history first......... For all you '....just-having-a-browse-while-I'm-here-Forumers, the piston extension is the whatsit thinggy that the breech block sits onto and the main piston screws into! The Mk1 piston extension and piston was apparently wasteful in manufacture because the lands between the piston rings of the Mk1 piston, (shown in the pic above) acted as what was described as a 'shutters' to the gas vents in the rounded part of the Mk1 gun gas cylinder. If you look carefully, you'll see that these lands block the openings of the gas escape or vent holes when the piston/breech block /piston extension is forward, effectively sealing that part of the gun from dust etc. Anyway, because of this, the male thread on the piston and female thread of the piston extension and the milled slot for the keeper/anti rotation pin (the subject of this discussion) were all index linked - or just indexed in engineering terms. This caused an intolerable amount of wastage according to the reports. Quite why is a bit of a mystery because once the machines have been properly set up for unskilled workers, it should be a doddle - but there you go. So a solution was found and out came the Mk2 piston without the lands or shutters. So with the Mk2 piston, it didn't matter where it screwed-in to, it bottomed out and was rotated back to align the holes and that was it. And if dust and debris/water got in, that was tough!

The IMPORTANT thing that was paramount during this development was that there was to be no what we now call, 'mixed fleet' Mk1 and 2 pistons had to fully interchange and operate with the original off the shelf piston extensions. That was pretty much what happened when any parts were developed and as we all know and understand, that's what made the Bren such a reliable and versatile gun. Even parts from the newest Mk3 or modified Mk4 or earliest Mk1 would interchange if push came to shove. And because the Inglis Brens were all made for the UK Government vide the Ministry of Supply (Oh yes they were.........., the contract to manufacture at Enfield between ZB at Brunn specified this and was extended to Lithgow but not to SA where they wanted to manufacture them too.....) any variations were very tightly controlled.

I'll give you an example. During a shortage of tubular brass rivets, one manufacture suggested that they could seal the end of the webbing Bren wallet straps by impregnating the ends with a plastic resin that would gel, set and prevent the ends fraying. Yet even this had to be submitted, tested, approved and sanctioned by the Ordnance Board - in the UK! And to utilise 400 or so bipod brackets that had been drilled slightly oversize, could they use oversize bolt shanks (not the thread.....) to save wastage and/or eliminate the need to bush them. Once again, it was approved BUT only on the condition that these bipods the legs were fixed permanently so that there was never a question of non interchangeability or a mixed fleet situation. You can see where I’m going can’t you………….?

There is no doubt (? Or could there be….) that these mystery pistons and piston extensions were indeed made at Inglis but the details of such a modification don’t appear in the papers here. ON that basis, they remain a mystery. But of this you can be sure. If the idea had been submitted, it’d have been rejected sharpish as it would have immediately meant that there was a mixed fleet. I also wonder why Inglis per se would go it alone and even consider a push-fit piston/piston extension a viable modification so late on in the war when they’d already successfully manufactured hundreds of thousands of the up to now fully interchangeable ones! Anyway, in a roundabout way, those are my views and ideas. I don’t think that the position of the markings on a component matters as these were done, hand held, with a foot operated punch (no health and safety then chaps…..). As for quantities, well I haven’t got my records handy at the moment but we have about 4 different records of Inglis production including the contracted MoS figures and all seem to tie up reasonably well. Britain did take a quantity of the 7.92 guns because the MoS shipping records and some of the OT and CH serial numbers appear on the ex 7.92 breech blocks now fitted to early 7.62mm L4’s.

It’s lunch time now and we’re having a well deserved Mess lunch and the rest of the afternoon off……………………..

[Kev G]

[QUOTE=Peter Laidler;140494]I read exactly what you say about the possibility that the 'mystery' 7.92mm Brens have a differently configured piston and piston interface connection.
<SNIP>
The IMPORTANT thing that was paramount during this development was that there was to be no what we now call, 'mixed fleet' Mk1 and 2 pistons had to fully interchange and operate with the original off the shelf piston extensions.
<SNIP>
.....any variations were very tightly controlled.
<SNIP>
There is no doubt (? Or could there be….) that these mystery pistons and piston extensions were indeed made at Inglis but the details of such a modification don’t appear in the papers here. ON that basis, they remain a mystery. But of this you can be sure. If the idea had been submitted, it’d have been rejected sharpish as it would have immediately meant that there was a mixed fleet. I also wonder why Inglis per se would go it alone and even consider a push-fit piston/piston extension a viable modification so late on in the war when they’d already successfully manufactured hundreds of thousands of the up to now fully interchangeable ones! Anyway, in a roundabout way, those are my views and ideas. I don’t think that the position of the markings on a component matters....
<SNIP>
As for quantities, well I haven’t got my records handy at the moment but we have about 4 different records of Inglis production including the contracted MoS figures and all seem to tie up reasonably well. <SNIP>QUOTE]

Peter from what you have mentioned regarding autherisation for modifications is it more likely these were made post war ?
Or 'B' post was for a country/end user that wasn't party to this agreement ?

If the 'mystery'/'sterile' guns did run with consecutive serial numbers and Iglis production and MoS figures tie up reasonably well, is there gaps in known highest and lowest 0T and CH 7.92 serial numbers to allow for 18,000 plus 'mystery'/'sterile' guns ?
If not would this also indicate they were not WW2 production ?

Sorry for any confusion ,when you replied "I don’t think that the position of the markings on a component matters.... " I was refering to the point that the guns themselves do not have any inspection or acceptance marks on them.

Clearly these Brens exist so it would be interesting to find out more infomation on them if anyone has anything to add.

ATB Kevin

[Brit plumber]

Has anyone asked if these were for the CIA? They did afterall have Canadian arsenals produce sterile unmarked 7.92mm ammo.

[Kev G]

BP see page 3 of this thread regarding MGMikes comments.
".... strongly suggest the involvement of an agency of the U.S. government."

ATB Kevin

[WallyG.]

Just wondering if the receiver metal finish might give any clues... the two sterile receivers I have appear to have been cut (main body) either with old tooling or in a hurry and set ups took deeper cuts than normal... as there is a consistant irregular surface to the receiver... or were polishing steps left off... posible indications of late production on worn tooling... for not to picky clients? My other Inglis guns seem to have a bit more finished surface.

[Peter Laidler]

First answer/question for BP. If Canada did produce this so called 'sterile' ammo for the CIA, then how do we all seem to know about it? And you all know the intelligence guys response to these 'sterile' weaponry is. As Major George xxxxxxs said when I asked him, '......It/they might be 'sterile' for 30 seconds until the obvious becomes obvious'

It just seems as it this thread is now going in one direction, asking two or maybe three questions.
First, what's the answer to the un-threaded piston and piston extension question. Many of which, but my no means all, were fitted to certain, very probably Inglis made 7.92mm guns? My opinion is that this is a post war, quick fix, by someone (?) to use up a load of unfinished bits.
(A bit like Leyland cars using up all their old 12" wheel/tyre/brake components from the 1100/1300CC car line on the formerly 10" wheel mini's............)
And secondly, were these seemingly 'extra' 7.92mm guns counted in the end-of-war census of totals
Or thirdly, were they, as astute Wally G has picked up, late, maybe unfinished and more likely, unnumbered and therefore uncensussed and uncounted production that was in the system or maybe unfinished after production ceased. Could these have been 'acquired' and made up over a period of time from unfinished parts. This could also account for those, like Wheaty, who say that a big pile of these 7.92mm Brens were suddenly 'found' in the 60'sss or so (sorry for doubting that now Wheaty.......).

After all, the gun trade isn't beyond a few shysters who would and could make do and mend and more importantly, earn a few ££'s on such a deal. After all, anyone could get a body marked BREN and engrave before it 7.92. Or better still, an unmarked body and engrave it 7.92 BREN Mk1. But it'd be a bit more difficult to engrave the Chinese characters! Once again, that's only my opinion.



After reading and re-reading Wally G's well thought out theory, this is what I think. After all, it's not beyoi

[Kev G]

First answer/question for BP. If Canada did produce this so called 'sterile' ammo for the CIA, then how do we all seem to know about it?

"...how do we all seem to know about it?"- I expect Oliver North during the Iran Contra affair asked himself the very same question ! LOL

Questions regarding this are probably best directed to the IAA (International Ammunition Association ) website as the 7.92mm and 9mm headstamps have been dicussed there.Also if of interest the 7.62x39mm ammuition made in the US for the Cambodian FANK.

And you all know the intelligence guys response to these 'sterile' weaponry is. As Major George xxxxxxs said when I asked him, '......It/they might be 'sterile' for 30 seconds until the obvious becomes obvious'

I don't think anyone is suggesting they were not ment to be traceable as to manufacture but the lack of markings and un-documented serial numbers make any gun'deniable'which is probably the best you could hope for.

It just seems as it this thread is now going in one direction, asking two or maybe three questions.
First, what's the answer to the un-threaded piston and piston extension question. Many of which, but my no means all,< ALL the 'number-xxxx' serial number Brens under discusion that I am aware of are fitted with a push fit piston > were fitted to certain, very probably Inglis made 7.92mm guns? My opinion is that this is a post war, quick fix, by someone (?) to use up a load of unfinished bits.
(A bit like Leyland cars using up all their old 12" wheel/tyre/brake components from the 1100/1300CC car line on the formerly 10" wheel mini's............)

And secondly, were these seemingly 'extra' 7.92mm guns counted in the end-of-war census of totals
Or thirdly, were they, as astute Wally G has picked up, late, maybe unfinished and more likely, unnumbered and therefore uncensussed and uncounted production that was in the system or maybe unfinished after production ceased. Could these have been 'acquired' and made up over a period of time from unfinished parts. This could also account for those, like Wheaty, who say that a big pile of these 7.92mm Brens were suddenly 'found' in the 60'sss or so (sorry for doubting that now Wheaty.......).

To quote Warren "A large number were found in Canada around the 65-70 period that had not been shipped to China. The estimate ran from around 50 to 200 units."
If these were Chinese contract guns surely they would be 0T & CH serial numbered guns ? Not 'number-xxxx' guns ?

As you mentioned Peter "I will have some firm comments on these oddball serial numbers soon. I cannot comment yet because the Bren book disc is away being publishd as we speak and it's also on my old computer during a changeover of computer and systems "
It will be of interest to see what info you can glean when you can refer to the computer.

After all, the gun trade isn't beyond a few shysters who would and could make do and mend and more importantly, earn a few ££'s on such a deal. After all, anyone could get a body marked BREN and engrave before it 7.92. Or better still, an unmarked body and engrave it 7.92 BREN Mk1. But it'd be a bit more difficult to engrave the Chinese characters! Once again, that's only my opinion.

The 1st option of anyone adding 7.92 to a body just marked 'BREN' is not possible as the font size of 'BREN'is different between the MK2,0T and 'number-xxxx' guns,it would have to be option 2 an unmarked body.

After reading and re-reading Wally G's well thought out theory, this is what I think. After all, it's not beyoi

I have no idea where and how they come about but would like to know.MGMike has so far furnished some very intresting info in his posts but hopefully more information will come to light in the future.

I respect your opinion that it is not beyond gun trade shysters to make these up from unfinished parts,But after all that trouble how and why they decided to get 2 examples back into Canadian Arsenals Limited after they had done them I can't quite comprehend.

ATB Kevin

[John R.]

The intelligence community usually (when they're able to be asked about such things.....) cringe at the notion of 'sterile' weapons, especially firearms. This is for many reasons. The principle one is that guns are made for killing people and once (if?) they are recovered, it doesn't take a brain surgeon to immediately identify the basic points of a) who made it and b) where it was made. These are inescapable facts. The next reason is that...................... anyway, the notion of using sterile light machine guns is a bit.............. Additionally, when weapons are fed into these 'groups', they are left marked simply so that the source of supply can be whitewashed - if that makes sense.

These are the words of an intelligence Major.

But back to this gun in particular, it looks to me like this is what we'd call now, a bit of 'identity theft' or in used car parlance, 'a bit of old fashioned car ringing'

You should see what your neighbours across the channel think is a"STERILE" weapon.

We had a few MAT 49 SMG's that sort of 'filtered down' from BIAFRA to Rhodesia and aber natuerlich wound up in the WRONG HANDS(i.e., blackish ones).

The tops of the receivers were roll stamped as follows.

Manufacture Nationale D'Armes Tulle

Modele 49

No.______ (blank space)

Holey sheepschitt ! Silly damned Ferogs just compounded the felony by leaving OFF the serial numbers.WHO could snaffle UN-NUMBERED SMG's out of a FRENCH GOVERNMENT ORDNANCE PLANT without serial numbers ? Better to have numbered them randomly USING THE SAME S/N groups as were shipped to French CLIENT States elswhere in i'Afrika; n'est ce pas mes amis ??

[John R.]

Has anyone asked if these were for the CIA? They did afterall have Canadian arsenals produce sterile unmarked 7.92mm ammo.

That so called"STERILE" 7.92 ammo was produced in the 1943-1945 time frame by Defense industries of Verdun,Quebec for use in BESA MG's and Chinese 7.92 Brens.It was NOT produced by Canadian Arsenals or even DOMINION ARSENALS(Valcartier,Quebec) and the CIA hadn't been heard of until AFTER WWII.

I had 1000's of LOOSE rds of the stuff and shot it all off in one of Warren's 1960's discovered 7.92 Brens(BRAND NEW IN THE CRATE IT WAS TOO) and my MG 34's and MG 42 as well as a K98 High Turret Sniper that I still KICK MYSELF for having sold off !!

Hindsight is ALWAYS 20/20 isn't it ??

Cheers,

JR