You can either waste your money on aftermarket mags that WILL fail you, either on Day One or someday soon after, OR you can spend your money on USGI or other quality military-contract mags and know they'll work.  You'll end up doing the latter eventually, so it's cheaper if you do that from the beginning.

Top of the list:

- USGI (see the Mag FAQ for brands)
- British steel AR mags (these are military contract)
- Sterling AR180 mags (though I'd rather see you sell these to owners of original AR180s)

After you've shopped from the first list, you might consider:

- Beta C 100-round dual drum (high cost-to-round ratio)
- MWG "The 90 Rounder" snail drum
- Thermolds (don't kid yourself: NOT as reliable as USGI mags)
- Orlites (ditto, and certainly behind Thermolds)
- PMI/Fed Ord aftermarket mags (fairly rare)

Avoid:

- Everything else, unless you're buying mags to be RANGE TARGETS


Of course, it's YOUR money, but this is the advice of collective experience, painfully and expensively learned.

-Troy