Honestly? I'd say that neither is really up to the task for a ~2.7" bore, particularly if you're looking to get the most out of 500 psi. Thank you for the detailed reply. Firstly, I apologise for listing the wrong solenoid valve. The valve I listed is the 1/2" model, but the same valve does come in...

Looking at building a simple, but powerful pneumatic cannon. This post is my attempt to gain as much information regarding my build before purchasing or finalising the design. In regards to specifications, the cannon will be a single shot muzzle loading variety, with a barrel diameter of approximate...