Sometimes there is some stupid questions on here. In short, just use issued eqpt, as its standard, and there are many varieties of M16 30rd mags ranging from plastic to steel, and many Chi-Com ones which are inferior products.
Steel ones will defeat the alloy housings of the M16s/M4s over time. Murhpy's law always prevails, and I would not want to see inferior mags trickle into the system, and somehow end up on operations. With many countries now using M16 mag design, now known as 5.56 x 45mm STANAG 30rd mags, I have seen Malaysian, US, French, British, Israeli, and even mags from Singapore floating around here.
Simply maintain what you have, and don't purchase foreign made stuff, as it might look the same, but it may be crap instead. Never transport prohibited stuff accross borders either, as you could end up in dirty great pile of shyte over it.
Canada uses stock standard alloy US mags for their C7/C8 families, and the mags are okay as the design has been on general issue since the early 70's in the USA. Prior to that, 20rd mags were standard, and there are thousands and thousands of them still here within Australia. US alloy 30rd mags are standard for the M4s here.
We can all ***** and complain about mags, but I am sure they are much more plentyfull it the SHTF in theatre.
Here 30rd 5.56 x 45mm plastic F88 mags are common, and its no big deal if one is lost or damaged. F88 mags are only common to the F88 and no other design. In my M83 AUSCAM LBV, there is 10 mag pouches, but here in Australia its 7 mags general issue, but rarely do we get 7 mags, usually 2 or 4 for exercises here.
As for chargers, we have them in bandoleers of a cotton OD bag with 10 pre-loaded charger/strippers all in one. The chargers fit both F88 and M16 mags and each charger holds 15 rds.
When in the CF I never heard of pre-loaded 30rd mags in bandoleers, but in the old US cloth bandoleers, one could fit a loaded 20rd mag into each pouch of the bandloeer, which may have gave the impression that there were such things.
When in the VN the US only 18rds of ball was loaded into each mag, and this was the same SOPs in Viet Nam for the 20rd 7.62mm mags for the L1A1 SL rifle.
Cheers,
Wes