This morning i was watching some oln gun show with competitive handgun shooting.  I think it was called USPSA or something simular.  Well anyway in the show they showed what every shooter was using.  And every shooter had some type of gun in .40.  I was just wondering why would they choose .40 caliber over 9 or .45 for competition use?  

Because the 9mm would hit the target and bounce off while the .45 would destroy the whole back of the range.

btt

Because .40's can be loaded to major power, and still be controllable by most shooters.  When I used to shoot IPSC/USPSA, I'd load my Wilson LE/K with 200 grain H&G #68 LSWC, 5.5 grains of Bullseye and CCI primers....chrono'd out at 177 power factor, with the threshold for major power at 175.

HH

9mm won't make major power factor, .45 will but comp is not as effective as low pressure round so that leaves.......40 or 38 super loaded to +p or the likes. If no comps are used it's for power factor and higher round count then a .45.

They have to make a certain power factor (bulley weight x velocity = PF) and 9 would be too small and 45 is fine, but a little bigger than it needs to be and magazine capacity starts being an issue.

The IPSC motto is DVC (diligentia, vis, celiratis) Accuracy, Power and Speed.

IPSC shooters will also employ 38 Super, 9x21, and even 9mmMajor (if they're using Glocks) to find the best combo of bullet weight/speed and recoil.

Regular old 9mm is making a big come back with the new-ish "Production" division.

You'll see a lot more 45 next year thanks to them copying IPDA CDP (1911's) division and calling it the "Provisional Single Stack".  Currently people are using 1911's with those 10 round magazines in the Limited-10 division - and I for one am not a big fan of the 10 rounder.

If you liked what you saw - you should swing by and check out a local IPSC/IDPA match.  You'll see how us petty humans shoot (a little slower than the dudes on OLN).  Be careful you don't get sucked in like I did.

You were watching the USPSA Limited Nationals. Almost everyone in that division shoots a 40 due to the fact that it makes a Major power factor. A 9mm makes Minor power factor and a 45 make Major. The reason people use a 40 over the 45 is round capacity. The 40 holds more rounds. The target is divided into 4 different scoring zones, with a Major power factor, you score more points than in Minor. You can get a lot of info at www.uspsa.org There are several different divisions to shoot in. Open, Limited, Limited-10, Production and Revolver.

GlockSpeed31