0.... I shoot mine atlest 150 rounds a year, if that. I do not want high millage on my carry peice. I know how it works, and how good of a shot I am with it. Glock 19, that I do not need to keep wearing it out. I will buy another Glock 19 to train on if I felt I needed to get better with it. I have done some drills at 7,14 and 25 yards. I feel confident I can use my peice at long range if I needed to hit say a car moving toward me. Mine has about 800-900 rounds through it and is 2 years and a half almost. I think it's a good idea for people to have an extra main carry peice so you can train with one and carry the other. I wanted to get another Glock 19, but I just spend the money on other guns lol..
It did take me a while to train on my j frame S&W, had to shoot it a bunch of times to get those pesky sights lined up. This is the gun I will shoot a few times a year to keep up my aim skills on, those sights are hard......