If you’re too slow on that first mag change, you might not need a second magazine.
Matthew Bracken – In Praise of Duplexed AR-15 Magazines
[I can totally grok this comment. He explains a method for duplexing two 30 round mags I will give a try and see how they work. There are a few serious advantages I see to duplexing this way, especially when needing to get into the fight fast and flat footed. I’ll do a write up and let you all know how it goes. –B]