Info on the KP-# series marker
The KP series
The KP is a Sheridan type pump. It shares many design similarties with the PGP pistol also made by Sheridan. The KP came in to production in the early 80's and went out of production around 1991, I am not sure about these dates, if you know for a fact what they are e-mail me. At the time of it's release it was one of the most formidable stock class pumps out there. It is the only gun to come with a beautiful wood stock right out of the factory.
I do know they started in the early 80s and shortly after converting to the
KP3 in 92 they stopped making them. I also know that they were a regular
airgun that Sheridan made for years and converted the barrel to larger brass
to make it paintball compatible. (from a source at WARPIG that I have been talking too, more info on the way)
KP-1
The KP-1 was the first in the series, it was purely a stock class gun. It had an intresting cocking mechinism to it. Instead of using a pump action it actually used a bolt action to cock it. The KP-1 runs off of a 12-gram powerlet and carries to my knowledge 14 rounds in a horizontally mounted ball tube.
KP-2
The KP-2 is basically the KP-1 with a pump action. It carried 14 rounds in a ball tube on the right side of the barrel. with all Stock class KP's, you need to rock the gun to the left and cock so that the ball falls into the chamber.
KP-2 DF
The DF stands for "direct feed". It was a KP-2 that instead of using a 14 round ball tube, it has a bulk loader or hopper, it still ran off of a 12-gram powerlet.
KP-3
the KP-3 was Sheridan's foray into direct feed, constant air paintball. Everything was factory-installed...there were a number of "aftermarket" tank brackets for KPs, but I think Sheridan's was unique. I believe it came with a 7oz. tank. Co2 was routed from the tank under the gun to an adaptor where the 12-gram would go. I suspect that it retained a 12-gram capability. Let me think...it also came with the "speed demon" bolt for easier fieldstripping (info provided by Jeb Hoge)