Newbie to Air Rifles Questions?

With airguns and accuracy its all about consistency. Consistent air pressure, consistent pellets (weights, sizes, shape), consistent shooter.

For air pressure consistency you want a PCP with a regulator. This will give you the most consistent air pressure through a string of shots. You will get a limited number of shots before the air regulator stops working. Google how PCP regulated airguns work...

You do not want high velocities with a pellet. They are primarily drag stabilized in flight. As you approach the speed of sound (~1125fps) you start to experience buffeting of the projectile, making it unstable thereby not accurate. Here is a good explanation... http://www.pyramydair.com/blog/2011/08/why-you-dont-want-to-break-the-sound-barrier/

Keep in mind accuracy means different things on this forum. You posted in the target shooting section, where say in BR we are striving to shoot 1/4 to 1/2 MOA VERY consistently, as in being able to do it (75) times in a row. Even in the more forgiving disciplines are looking for 1 MOA or sub 1 MOA accuracy.

You do not need this level of accuracy to shoot a rabbit or hit a pop can. 

If you don't need sub MOA performance there are a lot of regulated PCP rifles and pistols you can choose from. If you don't want a new gun, well a pumper is going to vary enough with equal pumps in air pressure to throw you off at any significant distance. Sorting pellets, testing different brands and types till you find the brand, weight, type your gun likes best. But don't have the expectation that you are going to shoot 1 MOA at 100y with it. You'll be lucky to shoot 12 MOA at 100y with a pumper. 

As for understanding the ballistics of airguns, I suggest you install a program called ChairGun from Hawke. With it you can easily play out different calibers and speeds and see the ballistics curves that result. It has a built-in list of pellets in several calibers. It will also do arrows and even 22lr. As an example my 30cal zero'ed at 25m drops about 16" at 100m.

Interesting post.

Percula has hit all the important points. In 2017, Air Rifles for target shooting (and hunting), are all about extreme accuracy within the range supported by the absolutely awful BC of diablo pellets. If you are prepared to calculate pellet drops over distances of < 100 yards, a PCP can be super accurate. Many (most?) posters on AGN are using PCPs rather than springers or pumpers, so a lot has changed since you used the 760.

Probably the three most widely used 0.22 guns in PCP are the Benjamin Marauder, various FX, and Daystate. Any of these will shoot extremely accurately, within their limits, but nothing like a rimfire for velocity/distance (which makes air rifles challenging/fun for those so inclined). Search postings on this site, or the websites for FX/Daystate/Crossman and you will see how far air guns have come.

Welcome to the forum Henry. Percula gave you the straight information. The results you got with your pump air rifle are about what anyone could reasonably expect. For shooting 100 yards, I would suggest 25 caliber or larger, unless you have the wallet to get one of the super high end 22 caliber air rifles. Even a velocity difference of 2 percent will cause a vertical strike difference of about an inch at 100 yards (assuming 25 caliber JSB exact king 25.39 grain pellets launched at 840 Feet Per Second). This means consistency of velocity is critical to accuracy. What Percula said about a regulated Pre Charged Pneumatic (PCP) is spot on. If you don't have the budget for one of the factory regulated rifles, other manufacturers (such as various Hatsan and Benjamin) have aftermarket regulators which can be purchased and installed in them to improve the consistency (accuracy).