What is the highest theoretical muzzle velocity possible from a gas piston rifle

[rsterne]

Not wanting to be a Negative Nancy, I will sit back and quietly watch your progress.... Perhaps a thread in the Engineering Gate would be more appropriate?....

https://www.gatewaytoairguns.org/GTA/index.php?board=164.0

Oh, and here is the thread on the 70 FPE Springer from 2015....  https://www.gatewaytoairguns.org/GTA/index.php?topic=94485.0 .... It was based on a typical swept volume in cc of 3 times the desired FPE....

Good Luck!!!!

Bob

[Scotchmo]

There are many practical limitations. For instance, in your example, how do you make that spring that weighs only 1/30 of an ounce but stores 500 foot-pounds of energy?

I wondered that, but assume it's the weight of the gas in the ram.

I was also making the same assumption

Maybe, but if it is assuming a gas ram, you will need to include the mass of the ram. 617m/s (about 2000fps) is certainly achievable, but that is nowhere near the theoretical limit of a piston gun. Even at 617 m/s, it will be an unpleasant gun to shoot and likely short lived. The high velocities are possible but the result will be high gas (propelling air) temperatures that you will have to deal with in your material selection.

Rather than the theoretical velocity limit, let's assume that 2000fps is an acceptable velocity. You want to shoot slugs at supersonic velocities. There was no mention of the distances goals. At 2000fps, a 25.4gr 0.084 G1 BC .22 slug would stay supersonic to about 100 yards. Your gas temperatures will be in the plasma range. And things are going to get heavy, so it won't be a field gun.

If you only want to explore the muzzle velocity limits, then you don't need high mass, high BC projectiles.

I haven't come up with any practical applications for supersonic airguns that can't be better met by subsonic. At least not yet. I still have some things that I want to try.

[WhatUPSbox?]

Choose your own path, but if this is meant to be an exercise of your engineering skills, I would avoid using someone else's online calculator or spreadsheet. The Tavella paper linked earlier, does a good job of covering the parameters involved in the shot cycle. You may decide to add or subtract terms based on your reasoning but your analysis probably should be at that level. As was mentioned, you will need empirical data for some of the terms. People here may be able to help.
Hopefully you didn't resell your thermodynamics and gas dynamics texts.