Long chokes work well. Often we see short chokes because they are easier and I expect cheaper to do. Anyone opening up chokes should use a pilot to keep your chokes centered Many use Mike O for the job. First thing is to pattern your gun to verify POI. If off you could adjust it when altering chokes. Going from .045 to .015 is a big jump. I might open one barrel to .025 and the second to .015 which has worked well for me in the past. Again pattern it to see if it meets your needs.