Here’s a picture of the first three models of paintball gun:
Here are some images of some current and popular “modern” paintball guns:
A paintball gun is essentially an airgun; there is a mechanism inside the gun (or attached to the gun) that holds gas under pressure, a mechanism for loading a projectile and a mechanism for a controlled release of a measured amount of gas that accelerates the projectile down a barrel as the gas expands.
The first paintball guns were essentially remodelled BB guns. Nowadays, paintball guns have gotten extremely sophisticated. There are all different kinds of models, from single shot derringers to multi-barreled BFGs.
Paintball guns have been designed to meet different market needs and different consumer needs. They now range in price from just under fifty dollars all the way up to a couple of thousand bucks.
Paintball guns have evolved significantly over the past thirty years. The original guns were single shot, hand-cocked pistols. A pump was added a few years later, making it much easier to cock. The “gravity feed” and the “auto-trigger” came next, allowing for more rapid firing of pump guns. This was followed by “constant air” that provided a larger gas reservoir.
“Bulk loaders” then arrived (allowing for more rounds to be loaded into the gun) and it wasn’t much longer before “auto-cocking” and semi-auto paintball guns were developed. Adding electronics and electro-mechanical devices came next which led to the development of electronic paintball guns and motorized “force-feed” loaders, which is pretty much the current state of the art.