Looking good.I modeled my .308 after the AA S510 TC and then made it in my design.https://www.pyramydair.com/s/m/Air_Arms_S510_TC_PCP_Air_Rifle/2386Don't know if the pics will show up due to Photobucket's ransom fee's.https://www.gatewaytoairguns.org/GTA/index.php?topic=82820.0
This is truly the most confusing thing ever, nothing works as expected.Case 1. If valve stem is practically air tight to valve body and thus doesn't let much air to the piston, the gun fires pellets with good velocity even with minimal mainspring tension but does not cycle. However autoloading works every time if magazine holes are blocked with tight steel pellets.Case 2. If valve stem is loose fit to valve body (radial clearance 0.1mm) I need to tighten the mainspring tension a lot to get the same velocity and if magazine is now blocked the gun will go full auto for a second or less but does not stay cocked. If the gun is fired with no magazine or empty magazine, the slide cycles almost all the way back but does not stay cocked after shot. Should I make that stem hole little bit bigger and just hope it will work, because if it doesn't I'll have to turn another valve body.
Nice going man, really nice! It is truly interesting to see your work, its always so different. Makes me feel like a hack, I'm just tinkering with stuff. Marko