My .308/7.62mm fullauto conversion- Plug & Play Success!!

[TactAdv]

Finally got around to looking at doing a .308 conversion for my '42 Daimler Mk II fullauto gun.

I've been picking up the various bits over the last year, finally got interested enough to put it all together,,,,litterally as it turns out. ;-))

I've been reading with much interest the various posts of doing the .308 conversions.....with all the ups and downs, so I now feel kind of sheepish to report to you all that, for my original gun at least, this turned out to be a "plug & play" exercise........not sure what to feel about that bit of luck but I'll report on my affair here.....

My receiver/gun as I said, and have posted several pictures around other posts herein, is a factory original condition Daimler Mk II from 1942, so that may/may not have turned out to be an important data point in this....

I am using one of the long-ago imported "South African"/DENEL/Lyttleton Eng. 7.62mm barrels that were new made for the SADF conversions there. Many of you seemingly have the same barrels.

I had been holding off on this project because, stupid me, I never really looked at the damn barrel carefully when it came in except to note the R1/FAL flash hider they used, which I think is a nice visual change for the BREn. Then one of you pointed out here that these barrels are markedly differently constructed in the that the barrel shank end is cut back, and chambered accordingly, to permit use of the standard .303 bolt with horns. I had been thinking I'd need to machine the barrel base for the normal .303 bolt, machine in the ramp to accommodate the feed horns a la the .303 barrels. That was a major discovery.... ;-))

In this particular combination of receiver & S.A. 7.62mm barrel, I was very lucky I think in that the combination breached up tight on the first try, and the bolt locked perfectly, with both the currently installed barrel lock and bolt locking shoulder. With that bit of luck, I checked the head-spacing and was in luck again. I swapped in a S.A. 7.62mm extractor into the normal .303 bolt it had in there, and that was it.

I am using unmodified Bulgy ZB-39 mags. I have read a lot here about using them for various things but wanted to try them first as-is. They took the full 25rds no problems. I was also lucky in that they locked in perfectly with the Mk II mag catch I had installed......

I decided to try some Russian "Brown Bear" steel case .308 I have lots of. See pictures below. The whole thing went together Plug & Play style.......I fired 160rds in various semi-auto and fullauto shooting, with only a couple of things to note.

As JoeH here pointed out, occasionally, I had the last round fail to get picked up out of the magazine. It was an intermittent thing, maybe 20% of the time. Interestingly, when that happened, leaving that single round in there, the gun would fire it if cocked again.

No failure to chamber or fire at any time, other than as above for the last round. I tried both gas port position #1 & #2. Both ran it fine, though #2 seemed, with this .308, to run more smoothly and I am guessing at about 600RPM or so.......I'll think about as I shoot it further. So far, so good.

Here are some pictures; I'll get live fire video next time out.
-TomH

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[browningautorifle]

We did one once using an 8mm Inglis. All we did was changed barrel(plus the minor fitting), checked headspace and carried on. Shot like yours does...used the same mag and bolt too...

[Joe H]

Tom,

I'm green with envy. FA Bren in the US.

Joe

[Lee Enfield]

[QUOTE=browningautorifle;334679]We did one once using an 8mm Inglis. All we did was changed barrel(plus the minor fitting), checked headspace and carried on. Shot like yours does...used the same mag and bolt too...[/QUOTE]

I assume you mean "...used the 8mm Mauser magazine and bolt too..." ?

[browningautorifle]

used the same mag and bolt too...

Like I said, used the same mag and bolt too...the ones in the gun. And, they worked fine.

[Peter Laidler]

Must have had an extractor change surely! I have just used a .303 BB assembly in an L4 gun (not the same I agree....) with a slightly dinged/distorted drill round (to replicate it having been fired and tight in the chamber) and the 7.62 drill round just moves to the rear a couple of mm's, then upwards slightly and slips off the extractor. It's not exactly comparing like with like but the mechanics of it are the same.

The trouble with a converted gun WITHOUT the magazine well stop inserts is that before long the gun feed lips will tear away. Or maybe this only occurs with those guns that use L1A1/FN type magazines that sit slightly deeper in order for the BB feed horns to make better contact with the smaller base rim diameter of the 7.62 cartridge

[browningautorifle]

Must have had an extractor change surely!

It was an 8mm gun boys, the 8mm extractor...and little square mag...he didn't have any 7.62 extractors so I know we didn't change it.

[Lee Enfield]

The 8mm Inglis Bren talk has thrown a kink into the conversation, can TactAdv show up a picture of the chamber end of his SA barrel?

There have been 3 different recent conversations which seem to have confused the waters:

- The L4 7.62mm series used 8mm Inglis Bren bolts & headspacing locking shoulders, so an L4 Bren barrel should lock into and headspace in a 8mm Inglis Bren assuming the use of the ZB26/30 8mm magazine.

- The "Government" SA 7.62 conversion used a modified .303 bolt (reducing ring silver soldered onto the face of the breech bolt) with a 7.62 extractor. the .303 bolt allowed them to continue the use of .303 locking shoulders. The barrels chamber end is contoured as a .303 barrel (if I understand correctly) to allow the use of the .303 bolt. The magazine well is altered to accept metric FN mags, and an ejector block fitted with a hold open was fitted.

- .303 barrels have been bored out and rechambered to 8mm Mauser, these barrels use un-modified .303 bolts which are fitted with 8mm Mauser extractors, newer condition Brens require some opening up of the rear of the magazine recess to accept 8mm ZB26/30 type magazines. This type of conversion "may have been" originally done at the behest of an unknown government user.

- current civilian owners of working Brens have mixed barrels, bolts and magazines in order to obtain guns which function in a variety of calibers (8mm Mauser, 7.62x54r, 8x56r(Austrian/Bulgarian/Hungarian), 7.62NATO, .303 British) which are available to owners...

---------- Post added at 08:32 AM ---------- Previous post was at 08:26 AM ----------

It was an 8mm gun boys, the 8mm extractor...and little square mag...he didn't have any 7.62 extractors so I know we didn't change it.

As far as I can tell, the 8mm extractor is the same as the 7.62 extractor....certainly much closer certainly than a .303 extractor..

[Peter Laidler]

You're all correct about the 7.92mm BB's and extractors and L/Sh's. These can be - and were - used un-altered in UK L4 guns. We know this because the EMERs stated it quite definately, the early parts lists identified them by their different drawing numbers and occasionally you'll see the 7.92 punched into them occasionally.

I understand that a very similar extractor, marked with a small letter T (for TANK) is also useable in a 762 or 792 gun as these extractors were for use in the 7.92mm BESA gun. But as I never had anything to do with BESA guns I can't confirm it. The last BESA's went in 1966/67 or so with the last Churchill tanks

[CINDERS]

How much do the brens cost as when I win my lotto millions I intend to move the whole lot of us over to the USA and buy a nice flat land with no neighbourghs and set up a a super longrange where the 416/478/ma duece could play as well bring in some brens/stens top it off with 6 sniper T's and get some ammo say 15oooo should do the trick