Dry fire is an important training tool, but the limitations are obvious. You practice with an empty gun and, unless your chosen weapon has a double-action trigger, that means you're limited to a single shot with a “cocked” trigger, with follow-up shots completed with a slack or dead trigger. The slide and sights don't move, so you don't get to practice sight-picture recovery after recoil. The gun is empty so it's much lighter than normal. Worst of all, it's boring as hell.
I decided to substitute airsoft for dry-fire. Gas blow-back (GBB) guns cycle the slide just like a real gun using a compressed gas propellant to fire plastic BB's at relatively low velocity. The slide cycling simulates the movement of your sights during recoil, forcing you to concentrate on re-aligning your sights after each shot. The gun also produces an audible “Pop!” sound when fired, which makes it easier to use a timer. CED makes a timer specifically for airsoft, the CED-7000A. The 6mm BB's also allow you to see where your shots hit so you can better judge your accuracy. Best of all, airsoft is safe for indoor practice, provided you wear eye protection.
I ordered a WE Model G17 gas blowback pistol from Red Wolf Airsoft. Made in Taiwan, the WE G17 very closely resembles a Gen 3 Glock 17 with a polymer frame, identical controls, and a metal slide. Without the orange tip at the end of the barrel, you would be hard pressed to tell the airsoft gun from the real thing, without a close inspection. The WE G17 even locks open on an empty magazine, so you can practice reloads.
Fully loaded, the WE G17 is only about 5 ounces lighter than the Glock. Lots of different designs are available. There should be one that approximates your competition gun. Another advantage is that the airsoft gun should fit your competition gear. The G17 fits into any standard Glock 17 holster, and the magazines will fit into any standard Glock magazine carrier.
The magazines are weighted to compensate for the lack of weight in the gun itself. They don't lose much weight as they empty out, either, so be careful when you're practicing reloads on hard surfaces. On hardwood floors they will leave a nasty ding, and you could damage them. The magazines are as expensive as their real life counterparts, so take care of them. If you're going to practice reloads, I recommend placing sofa cushions or something similar on the floor where the mags will fall.
I also purchased a box of 2/3 size IPSC targets and pasters and from Target Barn. The targets allow you to simulate actual competition targets at shorter distances. To simulate a seven-yard target, mark off five yards, 10-yards at seven, and 15 at 10, and so on.
I created my own target stands using 2″ PVC as well. My design requires six feet of 2″ PVC pipe, four T-joints, a can of PVC glue and one 1″x2″x8′ white wood board strips. If you want two stands, buy three 5-foot pieces of 2″ PVC, eight 2″ T-joints, and two 1″x2″x8′ strips of white board. Cut two of the 5-foot pipes into one foot sections, then cut the third pipe into eight three-inch sections.
Once assembled, cut the whiteboard strips in half so you have four 4-foot boards. These will be the uprights that hold the target. Using a pocket knife, shave a little off one end of each of the boards so that they will fit snugly into the 2″ pipes.
Using tape or a staple gun, attach a large pizza box top to the uprights. This will allow you to attach the 2/3 size targets to your stands. Just tape the targets to the pizza box backer and you're ready to go.
Setup time, including loading and re-charging magazines, is about 10 minutes. When you're finished shooting, just vacuum up the BB's and any cardboard bits. Tear-down and cleanup takes five minutes.
Once you have the gear and targets you can then set up your drills and shoot lots of reps without lots of cost. And with ammo prices such as they are, you can save a lot on ammo. You get great feedback on your practice, the cost of ammo and propellant is significantly cheaper than live fire practice, and you don't have to leave your house. You can even set up stages, based on actual courses of fire, indoors or outdoors, so you can practice situations for your next IDPA or USPSA match.
Airsoft will never replace live fire practice, but it can spice up your dry fire and be a fun supplement to your practice routine.