Also if you're not concerned about the 330fps legal limit paintball markers are manufactured to you can probably adjust the regulators (not just the velocity sc

Also if you're not concerned about the 330fps legal limit paintball markers are manufactured to you can probably adjust the regulators (not just the velocity screw you mentioned) to get a much higher initial kick. Or possibly use your own valve, that tank must output around 400-800psi before the marker regulates it down to somewhere like 200-300. And avoid feeding liquid CO2 into the marker. If there's a siphon tube in the tank it's fine that way up otherwise have the valve pointing up-ish.