BM: Here's a couple of other things to consider. A spring-powered airgun has recoil ... sometimes significant in the high-powered "magnum" guns. And it's actually in TWO directions, which can be death on scopes (use only real airgun scopes on springers). CO2 guns are temperature sensitive; and won't work well in low temps (has to do with the ability of the CO2 to gassify). As with all shooting, accuracy is dependent on consistent conditions; in the same way you'd want your firearm cartridges loaded exactly the same (same powder charge, same weight bullet, etc.), your aigun pressure from one shot to the next needs to be the same too; with CO2 it varies with temp. CO2s and Pre-Charged Pneumatics (PCPs) have no recoil. Springers are pretty quiet ... nearly silent; CO2s & PCPs have a definite "crack" (not as bad as a .22, but noticeable) ... and it's not uncommon to have "moderators" on them. If you're looking to use it for household/urban "pest control", and are worried about the neighbors, a springer is quieter.