Valve mod - pcp pistol

I am trying to make as much as I can, but will use a Crosman trigger frame and barrel. I have a steel breech which will save a lot of time, but would like to make a custom breech with a straight pull bolt that has a locking action rather than drop into a slot. very similar to my last build. That way I could get a little creative with open sights maybe.

It'll be .22. I do have a .25 cal FX barrel off an old Bobcat, but of course it'll need chopping down, but had thought about using that for a rifle build.

In the past, I have used delrin on the shaft which has worked well, but I was thinking of keeping the HP side of the valve stem to a minimum using metal which means the metal head can be made smaller and more streamlined.

"Therefore you can reduce both major closing forces on the valve:"

1) reducing the static pressure on the valve stem

2) reducing the dynamic pressure on the valve head

Of course, hadn't thought of brass or bronze. That would make sense.

With the screw driver shaft I don't need to change the diameter at all. I just cut to length then harden it. Giving it a polish afterwards.

I have about 1% metallurgy knowledge, but heat to cherry red or non ferrous state and quench in oil.

I have some 8 and 10 mm 316 round bar, but might take you up on the bronze alloy. Would only need a few small pieces.

The screwdriver shaft is not hardened only the tips are hardened steel. and you would find it very difficult to machine the hardened steel anyway. you will need grind it.

If it was me doing it i would be looking into 316 stainless for the valve and bronze alloy or brass for the seat. I have both here if you want to play with that. I have 10 and 20mm round 316 bar here. can easily make what ever bronze alloy you want.

Just a thought.