A while ago I needed some BS115 o-rings to overhaul my Daisy 717 target pistol, and eventually ended up having to buy a bag of 50 by mail order. Having fitted the o-rings, I can report that they work just fine. There are 2 of these in the pistol, one at the pump's piston and another at the cylinder to valve join. DIY guide for these pistols here: http://www.pilkguns.com/tenp/spd747.htm I can post out o-rings in exchange for stamps if anyone is interested? 3 o-rings for 3x 1st class stamps, drop me an email: numbnut -at- btconnect.com.