Real-cap, low-cap, mid-cap and hi-cap – what do these mean?
The ending “cap” comes from the word capacity. The prefixes tell how big the capacity is.
Real-cap, low-cap and mid-cap magazines all have the same design relating to the power that releases the BBs from the magazine. Each of them has a spring inside that compresses when loading the magazine and thus pushes the BBs out of the magazine, when the locking lug at the top of the magazine is pulled aside. A hi-cap magazine, on the other hand, has a more complex mechanism, with gears and a coil spring.
NB! Check out the basic instructions on magazine use from Tradetech.