extra as in a third magazine?
off the topic but Skennertonindicated both one and two magazines. and who can really say with a couple of millions of rifles spread out over 25 % of the world over a period of about 100 years among units in combat vs units in support positions in wars around the world almost constantly?
perhaps that document represents a period of time stated by Skennerton when there was a batch of deffective mags and a shortage of good mags? and would that one mag rule apply to units stationed away from combat in order to relieve the shortage in the combat zone? I dont know. but it is at least plausable. Skennerton does not go into depth on this. One thing he does state is that with the deffective mags. capacity was limited to 5 rounds.
. I can assure you when some desk warrior sent a memo like that down the line ( and they did often) it never stopped us from packing extra mags. Our unit armorer back us up on this too. Those extra mags were the ones the desk warriors never used. I had 10 extra mags shipped to me from home. I carried a browning hi power with two mags..... 6 more from home and I made sure every one worked first. Everybody from our capatain on down, understood and looked the other way.
so....
you might want to confirm this with the soldiers who actually carried one., two or more extra mags. You might be surprised