What is not clear from this is that the Lee-Enfield only needs one magazine. If you want to speed up loading of that installed-in-the-rifle magazine, get some milsurp .303 chargers (a.k.a., stripperclips).
Anyone that uses/carries multiple magazines for reloading their Lee-Enfield is a rare (and, perhaps, ignorant) bird.
Not really, but thanks for the non-THR compliment.
Magazines for the Lee-Enfield are often missing, have damaged feeding lips, and are ultimately expendable items. The cost and difficulty of getting new, unissued, magazines to replace an old one is now around $50-60 dollars and up. Even used and worn ones are bringing $35-40 dollars now and many used rifle parts websites no longer have them in regular stock. Garand clips were a dollar or two the last I checked and repros are still being produced. If a Garand clip gets damaged, then throw away. A Lee Enfield magazine, not so much.
Pro-Mags replacement magazines for the No. 1 and No. 4 are not very good and will subtract value from a rifle with one. Sarco has recently introduced replacement magazines that I have not used nor have any opinion about. The rimmed nature of the .303 requires good quality magazines to avoid things like rimlock and feeding issues. It is a fact, that those are getting scarce. Unless you know what to look for or the person kindly allows you to put something like snap caps in a Lee-Enfield's magazine, you will not necessarily know that the magazine needs to be replaced absent obvious damage to the feed lips.
There is a reason that British soldiers were issued a spare magazine. If the original magazine gets damaged, then you have a single shot rifle absent another good one. For better or worse, Mausers nor Garands have that issue.