20 Rnd Smle Magazines

Qs for Peter L. When we were discussing these you where on the point of telling me what happened to them when you were called away. So please do tell. Also after you returned and found me weak at the knees looking at the
L42 in the glass case you said something like it was or is the only one left in the MoD that message did not stick because you took me outback and showed me your own L42 and all those other goodies. Have arrived home to a small parcel with good instructions. Thankyou. Have contents etc been covered. The photos will be examined over the next week or so. Thanks again for a great time there maybe more Qs as i read my notes. So much eye candy so little time. Go see the Boss about knockoff time with a glass and ask how Scotland is.:D

Not to upstage Mr. Laidler, but I read somewhere that the magazines were bought post war for a automatic rifle project that went nowhere, and they were subsequently scrapped.
They were just as bad an idea as the german 20 round mags. Nice while you remained in the trench but a pain in the arse when you were advancing.

You're nearly right John but what actually happened accoprding to the reports we have is that during the late 20's/early 30's and into the ZB/Bren trials, the Vickers Berthier company were developing the VB light machine gun and at one time, it looked as though it might be the replacement for the Lewis gun with its twenty round rifle magazine. Vickers asked the Army for supplies of the 20 round magazines to speed up production of more trials guns. So, the total stocks of remaining 20 rounders were supplied to Vickers '...against further contracts'. I suppose that this was as a sort of part payment for subsequent orders for VB guns. Alas, the ZB and Bren were far, far superior and the VB didn't make it further than being purchased by the India Office.

Glad you enjoyed your couple of days with us Bindi

Presumably that where the remaining stocks of 20 round rifle magazines went to feed the Indian orders for VB guns. Maybe it's India that you ought to be looking in your searches for 20 round rifle magazines

Peter told us that the mags were purchased by Vickers after WW1 and were to be used on a Vickers Hotchkiss LMG developed in the mid-1920's. It didn't get anywhere (Army probably felt in had enough Lewis guns). Spot the mag in the picture.

I'd just last night been looking at some photos in Hatcher's Notebook of a couple of experimental Automatic rifles of this sort.
On page 99 the author is shown firing the "Berthier Machine Rifle of 1917" from the hip.
The magazine used in this particular sample has a waffle type reinforcement, it doesn't resemble the Enfield 20 round mag.

The "Hotchkis Machine Rifle", also of 1917 is pictured on page 108. the magazine used for this example may be an Enfield 20 round, but it looks to be straighter. Its likely a less curved mag used for a different cartridge.

The prototypes shown are possibly .30/06 versions since they were being tested by US Army officers.

The updated versions of the 20's and 30's had probably gone through many changes by then.
Those mags would have been handy for the Charleton conversion, if the springs used were up to pushing rounds upwards against gravity fast enough to avoid misfeeds that is.

For a time reproduction 20 or 25 round trench magazines for the GEW 98 were available, a bit too expensive though. Maybe someone will make a repro of the Enfield 20 rounder. Not really many applications for such a bulky mag on a BA rifle though. Two spare ten round mags would have served better.

The Lee rifles used by the US were often issued with belts of precharged magazines for quick reloads.

The problem with the standard Lee-Enfield magazine is that it was not really designed as a quick-change unit. Yes, I know that in the early days troops were issued with a spare: the main mag was also chained to the rifle. The L-E receiver is machined to control the feed of the cartridges. The rear mag lips work fine for retention, but the front ones are a bit marginal.

The cartridge retention in a Lee-Enfield mag is nowhere near as positive as that of the L1A1 or, in a bolt-action situation, the Accuracy International. You can take those mags filled with ammo and throw them around a bit, especially the L1A1. The AI not so much because of the much lower spring pressure required in a mag on a bolt action.

And there is the problem. On an auto, feed speeds are extremely high, thus the mag spring must be able to lift a full column of cartridges to feed position in the time between the bolt clearing the rim on its way to the rear and when it reaches the back of the cartridge column on the way forward: in the order of milliseconds.

If you then stick that magazine unchanged into a bolt action, the upward pressure of the cartridge column causes hugely increased drag during cycling of the bolt. Hence the AI magazine looks like an M-14 magazine but has a much "softer" spring. Compare a 10 round M-1A magazine and a SMLE mag for spring pressure.

Not only that, but in a bolt action, an excessively heavy spring will cause rounds to be "spat out" of the magazine during relatively slow cycling of the bolt. The inertia of the cartridges in the magazine is also a factor in auto mags. Getting the right balance is what good engineers do: enough spring "grunt" to lift the stack under duress, not so much that rounds pop out during sluggish cycling.

The M-14 magazine is a thing of engineering elegance. The two vertical "ribs" down the side of the mag case are not just there to stiffen the casing. As the cartridges rise in the magazine, they are supported laterally by just these two ribs. The rear rib bears on the web just forward of the extraction groove; the front on the neck of the case. This minimizes friction and allows for some dirt clearance. Kudos to Mr. Garand.

The M14 mags don't require too much force during the feeding cycle to hamper operation in the M85 bolt action. Main drama w/ the M85 is ensuring that the bolt will catch the base of the round to actually START the feed cycle.

Have heard using the 30 rd mags in the SLR can also be a problem as the spring is designed to force the rounds DOWN not UP, though that never stopped anyone from trying it on.(will have to try that someday as I have 4 new ones);)

Wasn't there a forty round magazine made for the heavy barrel squad auto version of the FN FAL?

Generally squad autos that feed from the bottom work best with some form of snail drum if more than 20 rounds of a main battle cartridge are needed. The lighter assault rifle cartridges work okay with thirty and forty round banna mags.

The BAR twenty round mag was considered sufficient due to the need to avoid overheating its fixed barrel, but the Polish quick change barrel version of the BAR was sometimes fitted with a belt feed mechanism.

Come to think of it, the "Mad Minute" would have been truly devastaing if a squad of riflemen had all been equipped with twenty round mags, especially if they carried spare twenty rounders.
Probably would have resulted in many more heavily eroded bores though.

Also I'd been under the impression that the 20 round mags had been used for the autoloader conversion of the Ross rifles. Or did this auto use a drum of some sort?.

The FALO (heavy barrel FAL) used a 30 round mag as far as I can remember, the 40 would not have allowed firing from the prone.