"The mag feeds the bb's flawlessly with no jams, even on full auto. Only problem is DBoys not only has the made in China cheap labor, but now I guess the recent models of these mags now have very cheap parts. I orderd two of these and both had the same problem, when you load the bbs into the mag, the spring-pressurized saftey on top, the thing that keeps the bbs from shooting out of the mag like lava from a volcano, stopped having pressure and the bbs would not stay in the mag. Problem was, the plastic piece behind the spring is very, very thin and snapped after one use. I manually repaired it by taking the mag apart and replacing the broken piece with a thick, solid piece of plastic or wood. As i stated i orderd two of these and both had the same problem and considering none of the other reviews before me had these problems, I am guessing its just a new recent production models that are manufactured to be as cheap as possible for manufacturing and price-wise safe. Now they work flawlessly and I am happy with my purchase. I use them in my M16A1 (Vietnam M16) by JG and they fit."