Lines of Effort
Effort Hopper is derived from ideas first floated in Efforts California, Connecticut, and New York.
With the aid of an H&K single stack magazine for their SL-8 rifle, we should be able to build and test a single stack hopper for the AR-15:
Many thanks to the designers at Heckler and Koch for jumping through the 922r hoops to bring the SL8 single stack magazine to the US.
Connecticut, with their demand that a rifle's action not be above the fingers of the trigger finger hand first inspired us to envision the AR turned upside down:
As you can see from the following pictures, we have arrived at a similar configuration, albeit with an evil patriotic stabby thing on the front: