Thanks for the input. I purchased a Guardian 13/3000 aluminum tank. The website says it outputs a consistent 800 PSI. I'll test this a bit more and see what happens. I'll have to try chronoing it again.
I noticed that farting for the first time today (thanks for the tip on pumping it hard). I'll make sure to back off in the future.
The pump just seems so elegant, and the magazine only capability is pretty cool too. I find a it more challenging having to manage my ammo, and I definitely lack the firepower in some occasions, but it adds another layer of realism.