There are times when an easily accessible holster is more practical and safer than your regular carry rig.
Range holsters are available in leather, Kydex and less expensive injection-molded polymer models. The two most common types of range holsters are the classic strong-side belt holster and, more recently, the leg holster. Adequate retention is always important, but especially so when training on a hot range with multiple shooters. Most range rigs address this with a combination of tight, precision molding and an adjustable tension screw or with a trigger-guard locking tab like that found on the Blackhawk SERPA.
Basic Rules: Concealed Carry Rigs
A good holster must be made for your pistol. Generic, one-size-fits-many models don't do a good job of retaining your pistol and are generally not very comfortable.
A good holster should be molded tight enough to retain your pistol without straps or tension screws, and it should cover the trigger guard. It should also have a reinforced mouth that keeps the empty holster open for easy one-handed re-holstering. The holster's belt loops or slots must match your belt so the holster stays put for all-day comfort and a sure, speedy draw.