The Oldest Debate

Frank Borelli Editor-in-Chief Officer.com The age old debate in the firearms community of .45 versus 9mm, or "big and slow" versus "small and fast" has once again reared its ugly head - but in a slightly different context than normal.  I was recently at the range where several of the shooters were qualifying with Glock Model 21 .45ACP pistols.  Others were qualifying with Glock Model 23 .40S&W pistols.  One guy was qualifying with a Glock Model 17 9mm pistol. Those qualifying with the .45ACP weapons had no issues.  They all actually shot scores that were in the high 90s.  The guy who qualified with the 9mm had no issues, also shooting a score in the high 90s.  Three officers were shooting the .40s and one of them was shooting as well as he wanted to - or felt he was capable of.  Upon reflection I had to wonder if the recoil of the .40 played any roll in his scores.  You see, he had previously qualified with 9mm pistols - and done so pretty well from what I understand. That thought brought forth this question: is it better to have a weapon of larger caliber if that larger caliber contributes to a measurable drop in your score?  We make the assumption that a drop in your qualification score has a concurrent and proportionate to your shooting performance in an actual life threatening situation. Some readers will answer that question, "No."  They believe that the caliber has no effect. Other readers will answer, "Maybe."  They'll want more specific information and perhaps to diagnose the shooter for themselves.  I understand that completely. For the sake of this conversation, let us assume that the caliber does affect the shooter's score in a negative way - no matter how little it may be.  That brings me to this question: Is it better to carry a 9mm pistol that you qualified 95% with or a .40S&W pistol that you qualified 85% with? I submit to you that an officer should - if given the option - carry the largest fighting caliber weapon he (or she) can that (s)he can qualify with to the highest standard.  What do I mean?  In my perfect world, the officer would carry a 9mm that he shot a 95% with instead of a .40S&W that he can't shoot better than 85% with. What do you think?