So, I received the mag from Dark Eagle yesterday. It is a very well built mag and you can feel it compared to the standard OEM mag. I did find that I could only get 9 rounds in the mag however, even with only feeding .260 rounds into the LA mag.

It does click right in to the mag housing though and feeds just fine.

Update: so I went back and read the instructions that came with the mag, (amazing right?) And there is a little trick you have to do to get the 10th round in... All is good now and I got all 10 rounds in. APPROVED!