Dry fire

Dry firing is the practice of "firing" a firearm without ammunition. That is, to pull the trigger and allow the hammer or striker to drop on an empty chamber. Dry firing may be mechanically damaging to some firearms – especially rimfire weapons, where the firing pin in most designs will impact the breech face if the weapon is dry-fired. Because of this, precautions (such as the use of "snap caps") need to be taken if such a weapon is to be deliberately dry-fired.

This technique is often used to simulate actual firing when there is not a suitable place to practice with live ammunition. The primary benefit of this practice is refined trigger control. For most common cartridges, there are snap caps available to reduce the risk of damaging the firing pin. It is generally acceptable to dry fire more modern centerfire firearms without a cartridge or snap cap. However, dry firing a shotgun or rimfire firearm can damage the firing pin. Furthermore, damage can occur to the chamber mouth of a rimfire firearm.

The technique allows people to conduct a safe, economical form of training to improve their shooting skills. An emphasis is placed on safety to prevent an accidental discharge. Training should be conducted in an area with no ammunition and with a suitable backstop. 10 to 15 minutes of dry fire practice a day is all that is recommended.

In recent years, a number of companies have developed methods of enhancing dry fire practice to improve skills. Products that fire a laser, as opposed to a solid projectile, have become increasingly popular. These include chamber inserts available for various caliber firearms, such as those made by Laser Ammo, as well as dedicated training pistols or replacement AR-15 bolt carrier groups, such as those made by Nextlevel Training. There are also a number of target systems for these laser dryfire training aides, that are becoming more affordable and popular, such as the Laser Activated Shot Reporter software. These products help people get more from dryfire practice by providing feedback on shot placement and times, and make dry fire a more enjoyable experience.

Dry firing in archery, termed dry loosing, refers to the loosing of the string of a bow or other weapon without ammunition, which should never be done. Without the arrow to absorb the energy, the energy is instead dissipated through vibration of the string, limbs, etc. Compound bows are particularly susceptible to damage due to high tension and numerous moving parts. Dry loosing a modern high-poundage compound bow even once may cause a combination of cracked limbs, bent axles, string derailment, cam warpage, string/cable failure, cable slide failure, etc. It can even cause the bow to shatter. While some bows can survive a dry loose with no damage, no manufacturers warrant their bows for dry loosing, and any bow that has been dry loosed needs to be thoroughly inspected for damage before shooting again. In particular, the limbs need to be inspected for cracking around cam axles and the opening of the slot where the cams or pulleys fit in (since they tend to tilt sideways during a dry loose).

Crossbows, with their high draw weights, are even more likely to be damaged by dry loosing.

Etymology
The term dry firing is most likely derived from the similar phrase "dry run (testing)", which is a rehearsal or testing process and in the case of the firearm, one is "testing" the trigger action and observing the hammer or striker drop, without using live ammunition. Sources indicate that "dry" originates from exhibitions by late-19th-century fire departments in the United States, where drills (runs) were conducted for public viewing without the use of water (dry).