Originally Posted by 300z
I never realized the barrels actually separated! Are all the internals unique or are they general nelson internals?
This is what I'd like to say:
"The two valves in a single housing are all standard Nelson Breech-drop until you get to the bolt.
(meaning the valve spring, cup seal, valve head, power tube, mainspring & hammer for each side are all pretty much "stock" Nelson parts and easy to get replacements)"
This is based on general configuration, I did not actually measure any parts nor have I tried to put in any parts other than original.
So I don't know about swapping parts with absolute surety, just that they look like every other Nelson valve I've torn down.
The bolts themselves are different from any other I've seen.
Each bolt has identical non-threaded linkage holes on both sides so they can go back in right, left, right side up or upside down equally & still connect to the pump arm; And the bolts are not threaded for any down-the-barrel velocity adjustment.