Prod can be filled to 3000 but mine shoots best filled to 2500-2700 psi at it's current 18 fpe tune. I increased it's velocity so it would reliably shoot through a squirrel broadside, but just barely. Works great for backyard pesting. Easy to refill with a hand pump. I can shoot it all the way down to 1000 psi with a little downward POI shift. That would mean about 35 pumps to refill. More typically I refill at about 1500 for no POI change and it is 20 or 25 pumps. Very compact and light. Mine wears a Hawke Vantage 2-7 and a home made stock and weighs about 5 lbs. For short range, 25-30 yards or less I think about 20 fpe is fine. If you want to go longer, for game no tougher than a squirrel I recommend 14-15 fpe at contact. I shot them with less when I got the Prod but had a couple run off with what I think were solid hits. Since getting it up around 18 fpe they have consistently dropped.
I also have an Avenger in 25 caliber. It's current tune is about 45 fpe for a 25.4 grain or nearly 50 for a 33.95. It shoots through squirrels easily but that means I have to be careful about what is behind them. It doesn't make them any more dead than the Prod but is capable of doing it at longer range, both from a power and accuracy standpoint. The Avenger is regulated so the only effect of higher fill pressure is more shots. I hand pumped it to 4000 a few times but it is a lot of pumps (I counted 250 from empty). My current regulator setting is 2100 so a 3000 fill would give me enough shots for a limit of squirrels (10 in SC).
If all you want to kill is small game I don't think you need larger than a 22. Shot placement is more important than power. Most larger 22 rifles will put out over 30 fpe at the muzzle which should be plenty out to at least 50 yards. But you have to hit the vitals. If you don't, more power doesn't fix it. If you want the option to brain shoot a pig or to kill raccoons or other somewhat larger game, then I think the 25 is indicated. But you will be pumping more and getting fewer shots.
