Hi,
IPSC competition is grouped, for scoring purposes, into divisions: a division allows people shooting comperable type of equipment to compete against either other, without any handicap. Think Formula 1 vs NASCAR - both car racing, but comparing the times of a F1 driver vs NASCAR is like apples and oranges.
The division where Glocks and Glock-like pistols ('duty style' guns) are mostly intended for is the "Production" division (unlike Open with highly customized race guns with optical sights) or Standard (slightly less customized than Std, but still based mostly on highly customized SA, 1911 style pistols). Production is where the normal guns fall into (Glocks, Beretta, CZ, etc). Production has a few rules on what guns/etc you may use if you want to compete against other shooters in that division, and one of them is the min 5lb trigger pull on the first shot. With Glocks, the first trigger pull is the same as every other one (unlike the more traditional SA/DA guns), so it means you need to have at least a 5lb trigger pull in your Glock. There are some other rules too, but that's the one which, I"m guessing, you're mostly dealing with here.
So, you might need to get a newer factory trigger part (I'm not a Glock person, there are trigger disconnectors, and other stuff - don't know what it all means), to bring your trigger pull to at least 5lb, and that's as high as you need to go. Then you'll be able to compete and have your times/scores compared to other people shooting similar style guns (and not $5000 race guns).
Also, in the Production division, you don't get any special "credit" for shooting a high power round (unlike in other divisions), so you can shoot your .40 Glock with light loads - the gun will eat up a lot more of the recoil, letting you recover from the shots quicker. That's why while most of the people in Prod shoot 9mm, there are those two prefer to shoot a .40 gun, and custom make their loads to be nice and light...
Does that answer your question(s) a bit?
