Rob, you're getting near. The sphere is the main part of your prescription, the magnification if you like. Base your shooting estimation on the "near" or "near/reading addition" of the prescription and make your estimation from that.

My right eye sphere is +0.25 and the near addition is +2.25 (near sphere = +2.5). I ordered lenses to +1.0 and +1.25. with the astig cylinder as prescription. At the moment, the +1.0 is correct.

My last pair of lenses from 2 years back were +0.5 and +0.75. As my eyes degraded I went from the former to the latter.

Whatever your own figures, your shooting lenses will be less strong than your reading lenses and stronger than your distance.

Sorry if I can't put it into better words!