You can buy really good shraders that are rated for over 3000 psi, but they are expensive, and you would still need to find a female shrader rated for the same pressure. It would be cheaper and easier just to use high pressure quick connects instead, which can be ordered from McMaster, or bought from a store that supplies hydraulic parts.
The position of the threshold between solid potato and mashed potato depends on more than just pressure. You have to take into account the length of the barrel, and how quick the pressure spike is. GGDT can show you the acceleration forces that are acting on the projectile throughout its movement in the barrel, so you just need to figure out what kind of G force it takes to mash a potato, which could be difficult, and would be widely dependent on the temperature, and the individual potato. A better option if you are going for high performance is to use a more durable projectile.
