Magazine matters

Just wondering: does anyone out there have any production drawings, dimensional and / or production notes on the various marks of magazine for the L.E., No1 and No4 series?

There are a few general diagrams floating about, but it would be interesting to compare the cartridge guidance and feed features across the generations.

I found the data for the Spring, Platform, Magazine. No2 for the SMLE a while back and would like to dig a bit further into the what's and why's of the subject, especially the changes made to make the system work with the Mk7 ammo..

On the subject of springs: I was always intrigued by the "auxiliary spring" in the front of the SMLE magazine. It seemed like a funny place for a spring that did not do much "springing". I was once told that it could be unclipped from the magazine case and attached to the end of the bottom leg of the mag. spring for use in adverse conditions. I tried it but it seems a bit dodgy.

However, the reason for its existence may be a bit more prosaic than that.

Whilst Mk1 and 1*had a folded wire magazine spring, quite in keeping with the late 20th century, the Mk2 Metford and its successors up to SMLE days seem to be fitted with a simple "clock" spring that was attached at the top front of the mag. case and curved down and back under the cartridge platform. The points (such as they were on Mk6 and earlier ammo) of the rounds slid up this spring as the magazine was emptied.

Magazines are a fairly close fit in L E type receivers, so, when the spring was changed to the well-known zig-zag shape, there were going to be a couple of "issues":

1. No more smooth, relatively hard surface against which the projectiles, especially the later spitzer Mk7, could bounce under recoil without denting the relatively soft material of the magazine case and making it difficult to remove and clean..

2. Given that Mk6 and Mk7 ammo is essentially the same length, there MAY also have been subtle issues with the way the rimmed cartridges "stacked", again under the influence of recoil, rough handling etc.

3. The simple expedient of clipping in a piece of folded spring steel sorted the preceding lot lot out without having to significantly alter the machining for the magazine well in the receiver.

Anyway, just my two bob's worth.