This invention is several months old but is notable because I’ve never seen it until now. It’s a box like device made by Maglula where you place an AR15 30 round magazine inside, and load up 30 rounds in the loader and the contraption automatically loads the entire magazine within seconds. At a price tag of almost 400 dollars on Brownells, it’s not for the casual shooter but for a company or a group that shoots thousands of rounds in a normal setting. DPMS has one for example and uses it in their rifle testing stations.
This is from a review on the Brownells product page for the loader.
I used this product at work for some 223 Rem testing we were performing. We had to fire over 4,000 rounds in this test. This loader is simple enough an infant could use it. All you do is lay the mag in it’s place, lay the ammo in a row and push the guide towards the mag and you are loaded and ready to go. I have not experienced any reliability issues with this product so far. If you frequent the range, this is a must. It’ll save your fingers some grief. It is a bit bulky, but if you are going to the range, that won’t matter. This isn’t something you would want to carry with you hunting.