Canadian Airgun Forum

Anyone shop for gas pistons retail?

This isn't exact specs as the Crosman F11 piston, but there seems to be a variety:

https://www.mscdirect.com/product/details/69150829

If you can drop it in & the PSI & stroke length is similar to or within spec of the more powerful American versions, how catastrophic are we assuming this can be? Lots of gas rams for furniture, some are super high quality stuff for advanced machinery. What would it take to custom order your own gas ram? Surely, that's what Crosman did. The $269 my F11 (495fps claimed) cost must be 3/4 piston alone. Something tells me that this gas ram isn't designed to strengthen from pre-tensioning. Hence why I'm just hobbying it up, seeing if I can improve it by sourcing a gas ram of my own.

Anyone tried sourcing their own?

Oh, and yet another question: In some YT vids I see people inserting the 'fat' end of the gas ram into the piston so it's "fat side to the front". Another YT vid showed "fat side to the rear". Mine seems to be designed for "fat side to the front", since the thin side of the gas ram is formed to accept the exact shape (see images). If it must be "fat to front", then if one were to modify it by installing a small shim, it would have to be the front side, right? (Left image).

Image upload is spinning forever, will try again later.

This is such a simple design - I'm determined to outsmart it, within reason. Gas rams aren't tough to source, but when they're custom - ouch! The old gas rams from the more powerful versions (same airgun specs otherwise) are a drop-in, apparently.

Gas Ram:

Length: 260mm
Body section length: 150mm
Spring section length: 110mm
Body section diameter: 19mm
Spring section diameter: 8mm

What I don't know:

Max Stroke: ?? mm / ?? decimal inch
Initial charge pressure: ?? PSI / ?? bar (I hear 60kg/850psi is ok?)

I'm impressed with how much I'm tolerated around here, with all these questions. "Don't encourage the boy!", lol.

- James