"I was looking for a speed loader for my AR-15 and originally was interested in the Caldwell Charger, but it didn't accommodate 300 BLK. So I didn't really research it any further since I wanted something to do both. I was on AR15.com and saw the ad for the Plate Design ACEM AR/M4 speed loader. The video sold me immediately.
It arrived in 2 days and I tested it today. It's as easy as the video shows. It has a channel to guide the rounds and the AR mag slides in easily. Tried PMag, Lancer, Troy and a few aluminum mags. Flawless and very quick. Since we cannot legally fully load our 30 round magazines before going to the range, this is a very simple solution. Nice solid design. They also make models for other rifle magazines."