https://www.milsurps.com/images/impo...6bnj79sg-1.jpgQuote:
Originally Posted by A. F Medic
MK3 magazine auxiliary springs will be a bit wider.
ATB Kevin
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https://www.milsurps.com/images/impo...6bnj79sg-1.jpgQuote:
Originally Posted by A. F Medic
MK3 magazine auxiliary springs will be a bit wider.
ATB Kevin
Here's a teaser for you Bren fiends. Do you know WHY the magazines were modified to accommodate the auxiliary spring - and late made that way...........?
I don't know the reason, but thinking logically I would guess that it might be to keep the rounds of rattling fore and aft in the magazine?Quote:
Originally Posted by Peter Laidler
Otherwise, I can only see it acting on the follower to keep it from hanging up on the inside of the magazine body, or to tension and slow the follower perhaps preventing double feeding, if that was an issue?
I am however curious to know.
Re. the "aux. spring":
I suspect it is remotely related to the reason SMLE mags have such a spring.
In the case of the rifle mags, the original very early mag designs used a peculiar lifting spring that was attached at the top front of the mag box and formed a semi-circle down and then back up to the bottom of the follower.
Changing to a more conventional "zig-zag" spring whilst retaining the same EXTERNAL box dimensions AND internal rifle dimensions, required a bit of "packing" in the form of the "auxiliary spring".
Furthermore, being hard-ish spring steel, it served as a better "running surface" as the cartridge stack moved up (or down). In the case (so to speak) of the later BREN mags, there seems to be a bit of welding going on along that front panel of the mag body
My guess is that the BREN version was used for this latter "smoothing" purpose and maybe to "fine tune" the stacking / presentation of the cartridges.
I also may be wildly off-beam.
To stop rim overs causing feed problems a right jam I am reckoning which will happen in the direst of moments
I'll just leave this here -
https://www.milsurps.com/images/impo...tipdent2-1.jpg
MKI mags without spring.
Say no more...... The recoil and momentum imparted to the rounds in the magazine caused the noses of the rounds to stub into the front face which caused the dimpling shown in KevG's photos. I know it's hard to believe, but it's true - as you can see. The same applied to the Boys rifle and an aux. spring was inserted into them too.
In truth, I have never seen an example of this before now and the true explanation tested my mechanical engineering theory. I mean......, how could a lead, copper jacketed bullet/round do this to a mild steel magazine. But get enough bullets hitting the mild steel magazine face and it does......... The spring is simply a spring loaded buffer that works
Go to the top of the class Kev!
I started tidying up my early mk1 Bren mag box last night by removing a few of the dents etc. I noticed that the box has Canadian acceptance marks on it and also below the current Nato green paint and a coat of browny green the tin appears to have been originally painted an air-force blue colour. This looks like the first colour the tin was. Does anyone know if the RCAF used Bren guns and did/does the Canadian air-force have an equivalent of the RAF Regiment for guarding airfields etc, please?
.....Hmmmm, it is really a "buffer"? Is the arctuate curvature of the "auxiliary" spring, when mounted inside the front of the magazine box body, laying in a stand-off position relative to the front sheet metal, giving it room to compress under load in a convex movement in the direction of the projectile tips? Or.....is the aux spring merely a convenient flat sheet spacer that merely takes up the un-needed space of the magazine box front side area, preventing only the translational movement of the projectiles tips under momentum loading??Quote:
Originally Posted by Peter Laidler
IOW's.....my suspicion is that it just keeps the cartridges from sliding back and forth. ;-)
-TomH
As an engineer, I can see and appreciate your point Tom. But the fact is that the spring acts as a buffer of sorts and prevents damage to the front of the magazine. This was an early problem when some well used magazines would not fit into place in the gun due to being held slightly to the rear by the stubbing/extending of the front area. The pictures illustrate this. Same applied to the Boys rifle and they changed that mag to the Mk2 version - with a spring down the front.
I doubt whether the .00X" thickness of the aux spring would make any real difference to the cartridges sliding back and forth - except for that .00X" of course