I would expect that you may find that.40 may be a bit more finicky to get to run than .45 all things being equal. Reliability is key, the more you chase that the less fun you'll have as your scores slip. Don't get me wrong, .40's can run but there is a lot of info on B.E. that indicates sometimes it can take some work. My Springfield in .45 would just shoot, dirty,wet, dry, hot or below 0..