This is from the article in "Velocity". Its an interview with Ernest and his P220.
Q. Did you make any modifications to the gun (Sig P220ST) before you started competion with it?
EL. Very little, actually. On any piece that I shoot much I go over the exterior of the gun and knock off all the sharp edges. SIGs don't really have many sharp edges to start with. There were only two areas I really worried about. One, I rounded off the sides of the underside of the trigger guard. When I'm standing there practicing, doing draw after draw after draw, the top of my support hand index finger is constantly slamming into that trigger guard. If I don't smooth that area out I'll get a blister before the day's out. Two, I grip the gun really high and sometimes the web of my hand will actually roll up and over the grip tang and into the path of the slide. I had to round off the rear edge of the slide or it was just a matter of time before it cut me.
I changed the sights, like all competition shooters do. I'm using a dawson fiver optic front sight. The same thing Robbie Leatham had on his 1911 at the IDPA Nationals this year, as a matter of fact. The rear sight is a prototype Scott Warren came up with. It looks like a standard notch rear sight except that the bottom of the notch, instead of being squared off, is rounded. That, along with the overall shape of the rear sight blade, really sucks your eye into the rear notch. I don't know when he's going to start selling it, but it's coming soon.
I also did some trigger work. The double action on my competition gun is about 6-pounds, and the single action is about 2-pounds. I've been playing around with the SIG triggers for a few years now. I've figured out some things, so much so that I now offer SIG trigger work through my company. I call what's been done to my gun the Level III trigger job. It entails polishing all the contact surfaces, changing the hammer spring, and installing a Speed Bump trigger that limits over travel.
The gun came with those huge, heavy Hogue rubber grips. I replaced them with wooden grips because the Hogues actually made the gun too heavy. (Any gun used to compete in IDPA CDP division can't weigh more than 41 ounces.)
Finally, I took a steel 1911 mag funnel and TIG welded it to the bottom of the mag well, because, as you know, in IDPA being able to reload fats is a huge deal, especially in CDP with an 8-round magazine where you pretty much know that you'll have to reload on every stage.