There's a loader built onto the stock on ban M3A1 to save your thumb. Works just fine.
You push that little L-shaped hook just forward of the *buttplate* down on the top round in a mag, and it presses the top round down just enough to drop in another. And it saves your thumb.
The stock can be useful for other things too: it serves as a wrench for the barrel if it's carbon-frozen onto the receiver. And it can be used in other ways, too, ask Skip.
