7.62mm L4 series........

[c310pilot]

All of this is very interesting. As my brain capacity is less than nothing right now, I had a 4:30am show today and a full day of flying, I will have to re-read this in tomorrow. My friend with the fa Bren has a CNC at his home. We like our toys, and can, and are willing to prototype. I have a 4:15 show tomorrow so I am off for some shut eye.

[ActionYobbo]

I had a thought while pondering the problems outlined here
just cut a slot in the side of the bren mag to allow the x54 rim out. then the x54 will bear on the case body inside the mag body. this will eliminate that outward pressure.start the cut above the mag well height on the mag.

just throwing it out there

[Peter Laidler]

I'd be starting with the tried and trusted old .303" magazines and go from there because they are another 'known' - in that they are an original FIT in your gun. The similarities between the .303 and 762R are just too great to ignore. But that is the starting point from someone who ain't tried it!

[Joe H]

All of this is very interesting. As my brain capacity is less than nothing right now, I had a 4:30am show today and a full day of flying, I will have to re-read this in tomorrow. My friend with the fa Bren has a CNC at his home. We like our toys, and can, and are willing to prototype. I have a 4:15 show tomorrow so I am off for some shut eye.

Hey C310,

Get plenty of sleep. The next time I take a US Airways flight and see you in the cockpit I want you bright-eyed and bushy-tailed .

Joe

[Joe H]

IMO to get a 54R mag that really works you will need to design the mag case geometry to fit the 7.62x54R round. Helper springs, follower mods won't do it.

It's been a very interesting discussion. IMO I don't think the case geometry of the .303 Bren mag can ever be converted to a hi capacity 7.62x54R magazine but I'd sure like to see someone do it.

My experience, taking into account comments already posted in this Thread, with the 7.62x54R is summed up in my original comment quoted above.

Joe

[Peter Laidler]

Good technical discussion and I am inclined to agree with that sentiment Joe. BUT....... I always remember that old saying. 'Where there's a will, there's a way' But better still, the corrected version of one of my old bosses. Where there's a will, there's usually a simple way. On the other hand, one of my '.....more recent' bosses, MUCH higher in rank to me, changed all that to '.....where there's a will, I can usually make it a difficult way! And he usually did!

I'd like to think that the .303" magazine is the way to go BUT get rid of the platform guide and use an articulated/find-its-own-level platform.

[TactAdv]

My experience, taking into account comments already posted in this Thread, with the 7.62x54R is summed up in my original comment quoted above.

Joe

.....being in the industry and having done a couple modern magazines, start to finish, and had them produced......let me throw out some numbers for you. There are at least four repop mags that have recently been done in S. Korea for the USA market....the M1 carbine mags (15 & 30rd), the M3 SMG mag, the STEn mag, and the old Mauser K98 trench mag.....these were all "copied", i.e., not built from original drawings so tolerances are hit and miss. These four were apparently done at rather low cost, less than $25,000 per design with minimum piece orders required. This represents the lowest cost to do a stamped steel magazine, when all you are doing is copying an existing article and in a very inexpensive labor and production market, i.e., Korea. These likely were all done on short-run aluminum dies, and the life expectancy of these dies is probably below 1,000 pieces.

For a customer three years ago, I did a reverse-engineer copy of the standard AKM stamped steel top-cover for a current production product here in the USA, the copied top-cover forms the base of a M1913 "Picatinny" style top cover optics mounting system- the 3 part progressive stamping die set cost $67,000 ALONE. Just the die set. Finalizing the dies to incorporate some additional late features cost another $11,000 to weld up and redo the first stage former.

I have done a 20rd 7.62x51mm M80 ball round magazine for the "AR-10" platform that used a four stage progression and cost right at $80,000. The last "big" mag I worked with was a close copy of the 10-rd Barrett M82/107 .50BMG M33 box magazine for a proprietary competitor of the Barrett that had been buying mags from Barrett but got cut off when he came out with a semi-auto .50BMG rifle that is now beating the Barrett in sales and performance. That mag job cost "only" $44,000 because the guy who needed it is in his own right a talented engineer and did most of the design permutations and CAD work on his own first, only taking it to the stamping house at the end.

Stamped steel is a wonderful application for mass production, but even in the digital engineering age, is still NOT cheap to play with to begin with. The only real way you can make money at it is by doing large scale production runs to offset the non-recurring up front costs.

Doing a modern "clone/copy" of the ZB29 mag is probably, at a MINIMUM, a $30K project to get to the first article stage and have a usable set of production tooling. So.....since this is only a hobby exercise, I am content with playing around with what we have to use as-is! ;-)
-TomH

[c310pilot]

I agree starting from scratch doesn't make sense. Joe H's design showed promise as it worked initially. Joe L. said the problems began to show up on the third or fourth load. The question is what is changing from a cold gun to a hot gun. The ZB follower also pinches the round towards each other. I would like to start with a new follower design and incorporate that into the zb mag. Machining new followers is a much less costly under taking esp being we have a CNC. I am not here to make money just feed the toys.

What is the width difference of the Lahti Saloranta LMG 20rnd 7.62x53R Magazine and the Bren? I would like to see the follower and do some tinkering. Curious how it compares to the width of the Zb26/30 8mm mags too.


Joe - I will have to pickup some Pittsburgh flights so I can give you a tour of the jet.

[Vincent]

Are the SGM Tactical VEPR 7.26x54R 20 round magazines adaptable to the Bren?

VEPR 7.62x54R 20 Round Magazine

[Joe H]

Attachment 58115

Are the SGM Tactical VEPR 7.26x54R 20 round magazines adaptable to the Bren?

Vincent,

Hard to tell without having one in hand. They are made of Black Polymer and are advertised as double stack to single feed which is what the Lahti mag is. It is also designed to feed up, the opposite of the Bren.

Doesn't look promising to me but I've been wrong before

Joe