I'm working on a sniper project. I've been involved in scenario for years and I'm trying to build a ultra quiet marker(PSL below 55db). I'm a 3rd year Aeronautical engineer, and am designing (almost done) a custom barrel extension that'll be attached to a lapco back.
Where I need your guys expertes and experience is with the upgrades to the internals. I've seen alot of videos with people shooting their "quiet" markers, and I notice that the actual pump stroke and internals are also loud. Too much metal-on-metal contact. I've been doing my reading and I know about having lower-pressure to quiet the marker. My main concern is getting rid of the metal to metal contact.
Here's the marker.
The loudest part is this medal piece in the back that holds the bolt pin. Do they make a non-metal version of this? or one that has a rubber gasket? I basically want to get rid of as many moving metal parts as possible.
Also I'd like some advice on what valve and regulator I should look into.