Originally Posted by
air-tech
They were sold in markets where telescopic sights were illegal. Looked very good actually with a blade front sight. My S300 also originally had opens fitted.
Also I don't know about the tapered bores on PE's. The piston seals seem to come off because they were barely "on" in the first place. Once the piston is removed, all you need to do is casually flick the seal with your thumb as if you were flicking a pre-opened beer bottle cap, and off it flew. Mine came unstuck after a period of disuse, the mild adherence of the seal to the breech block face meant that the piston travelled rearwards without the seal.