I'm a very new USPSA shooter. Just never really thought I had the resources or availability of matches. Anyway, shot my first match about 2 months ago and got classed in C Production.
Unable to spend every waking minute at the range I was trying to do more dry fire practice. This is something that I have done for years, but poorly. Just practicing trigger breaks, index and reloads. Never under the pressure of a timer.
After reading Ben Stoeger's book on dry fire he mentioned getting the slide out of battery for Glock dryfire. Eureka! I had never thought of doing that to allow multiple "shots". However, the "feel" was just odd to me. Somehow I discovered this dry fire mag on google after searching. The price was high, but decided it was cheaper than bullets.
Geocities website here: http://dryfiremag.com/
I've been using it for a few weeks now and can honestly say I recommend this for Glock shooters. It is extremely close to a Glock trigger break and more useful than the spongy out of battery method to me.