Same from me none of your selection of rifles. Look at second rifles for example a BSA R10 or Air Arms most RFDs have second hand ones in and usually offer a limited warranty for a couple of months buying of the net is not is not ideal as there are scammers about.

As to reading range just practice and practice some more. It’s easy when shooting at targets I know a lad who is amazing a target work but at field work he is about as useful as a chocolate frog. The last thing you want is to wound an animal what you shoot may be classed as pests but no matter what suffer. Use range finder go out into the field stick so,e markers out record the distance and shoot them and repeat it will help.

Also stop shooting animals until you a confident of a kill shot as you have said you are not getting kill shots.