Usually when the subject of what calibers/loads are used by large agencies who operate in pretty cold climes, it's seemed that 9's get 147gr loads and .40's get 180gr loads. (I mean when this subject comes up and is this being discussed among firearms instructors & armorers.)
While you hear of 230gr .45 loads being favored among .45 users, I've also had an instructor from an agency in the NE tell me his agency finally switched from .45 to .40 in order to get more consistent penetration and expansion in their duty pistols when engaging heavily clothed armed suspects in the coldest times of the year.
Seems to me the ISP, who used the 115gr +P+ loads made by Winchester & Federal for many years, didn't have any complaints about their favored load during different seasons.
Having used a variety of standard pressure, +P & +P+ 9mm loads over the years, I don't get too fussy about bullet weight anymore. Given a choice, I do prefer to use one of the better designed bullets, though.
I also don't hope for caliber, bullet weight & design or MV to offset any lack on my part when it comes to mindset, skillset, experience and being able to employ necessary tactics.
Sub Club #9; .40 S&W Club #1953; S&W Club #3913
Retired LE - firearms instructor/armorer
Last edited by fastbolt; 10-02-2012 at 11:41..