Efficient Valve Designs for 12 Grams

[Lane]

I remember on the old MCB there was an extensive post about getting the most efficiency out of a 12 gram with a nelson style valve (phantom). Are nelson style valves still considered one of the most efficient and consistent valves out there? With a 12 gram drop out changer off the back you can really limit excess volume and get pretty good numbers. How do they stack up to valves like the sheridan style when it comes to efficiency and consistency? Are there newer designs that push 12 grams even further?

[Jellyghost]

There was a name for that thread. Was it project Leprechaun? That would be a good thread to save from Wayback. Others with more knowledge will post, but my memory is that a Nelson valve gets 35-45 when carefully tuned. My nelsons get 30 without tuning. I think a well tuned sniper did the best though.

[spikeball]

The Project Leprechaun thread was a good read. There was a video in there of someone slapping together some nelson parts and getting over 40 shots off a 12 gram.
My stock class phantom can do 40 on a good day. Typically it's high 30's though.

[Painthappy]

Hard spring in the back, soft spring in the front, we also put a spacer in the valve to take up the access area.

[iamthelazerviking]

I've achieved around 40 off a 12 gram on a stock Phantom with silver main spring. I've always been a proponent of keeping the Phantom's guts as stock as possible. I don't recall paint used but it was warm weather and probably using a Freak bored barrel.

[Axel]

Here's Project Leprechaun:

https://web.archive.org/web/20180128183439/http://www.mcarterbrown.com/forums/custom-projects-custom-questions/146751-nelson-valve-evolution-project-leprechaun.html

And here's a "folder" of other Nelson tuning threads that Nish compiled:

https://web.archive.org/web/20180117142451/http://www.mcarterbrown.com/forums/pump-markers/183868-historic-nelson-tuning-threads.html