What bullets are best for a air rifle 177 or 22?

Answer 1

You mean What is the best PELLETS for an air rifle. This all depends on the current rifle you own. You can not use .22 caliber pellets in a .177 caliber rifle or vise versa. As for individual calibers them it's really up to you. .177 is more common, but I prefer the .22 because it is larger and has more knock down power. I even own a .25 caliber for hunting.

Match rifles use .177 caliber But unless you plan to own a $600 to $2000 match air rifle I wouldn't lets that influence me to select a .177.

As the calibers get bigger the pellets get bigger. Bigger pellets fly slower but fly straighter and hit harder. .177 pellets travel very fast but are more influenced by crosswind.

Beeman actually makes a interchangeable barrel rifle, one is .177 and the other is .22. It's the model RS2 at around $135 it's gives you the choice of both barrels. I'm not trying to sell you on it just letting you know what is available.