As a second thought on this topic I should say that over here in the UK there are a limited number of air rifles which can be supplied as "firearms" certificate versions....meaning they produce more than 12 ft lbs. These versions of air rifles tend to be towards the top end of the range of the "air bottle" type rifles and given that we tend to pay pounds for dollars these are rather expensive when compared to a .22 rimfire rifle.

As an example a Theoban air rifle which is powered to FAC level is about £800...a good .22 rifle from Anschutz is about £400...the cost of Eley subsonic rounds is £69 per 1000...therefore for the same price as the air rifle you could have a .22 LR and 5000 rounds...therefore for us it is actually more economical to have a .22 LR which is moderated and shoots subsonic ammo...I don't know if it is the same in the US but it seems to me that Air Rifles are unjustifiably expensive....plus you will be a fair bit more effective with a subsonic .22 rimfire round than an air rifle pellet.

That's why I sold my Day State Air rifle...got myself a Sako heavy barrel .22 and moderator and a fair bit of ammo...and that was on the trade in value...the scope I just swapped over and I still have'nt used all the ammo I got...I must have 1000 rounds left.