More done, linkage from charge handle to rear to be made and trigger needs a return spring, power seems low but that's what I wanted. The springs are about as much as I can push, rearward charging is definitely needed for more spring tension.

Grip made from 3/4" plywood. Trigger latch needed a bit of a detent to keep it latched

Got a real trigger made, pull is really light. Had to braze the springs together as the ends were binding on the guide as they moved, have 2 lengths to try.

pretty much all stainless steel

trigger mechanism working with light springs on.

a lot of force needed to compress it though

A bit of progress, bracket in the middle is for the grip, sprig guide needs a locking collar for the charge handle to push on, trigger not figured out yet or linkage to rear to load.

Anybody know the bolt pull/cocking force required on a typical airsoft sniper rifle? trying to get an idea of spring strengths I may need for a 100mm stroke piston, I have read that one has a 95mm stroke but can't find any force required data.

For a spring powered airsoft would a short stroke large bore piston work as well as a smaller bore piston with a longer stroke if they had the same displacement volume ? I'm thinking the larger bore piston would need a heavier spring but would be more compact length wise.

the only benefit I can see from the forward cocking is it would give rearward recoil effect

If this one works I plan on building another with double the size cylinder and barrel, probably forward facing cylinder as well for the compactness.

Experimenting with a self contained pump action airsoft using an air cylinder and springs to provide the power. Using a 1 1/16" bore X 2 " stroke cylinder. m_a17020dp.jpg Cylinder is on the top and facing forward which means it needs to be pushed forward to compress springs rather than backwards. Wi...

That's not too tight is it ? 0.249 ID

Anybody tried one of these Chronographs, for the price I'm tempted to get one, the large opening will work well for my Nerf guns as well.

I'm on a Nerf thing at the moment so converted it to Nerf Rival with a ball valve for loading and 3/4" copper barrel.