Tactical Breaching

Typical target locations for breaching a door at the latch (left) and the hinges (right).

Explosive Breaching

Explosive breaching can be the fastest method, though it is also the most dangerous, to both the breachers and the room occupants. Depending on the situation, explosive breaching is potentially slower than a ballistic breach due to the large standoff required when using explosives, if there is no cover available. Breaching can be performed with a specially formed breaching charge placed in contact with the door, or with various standoff breaching devices, such as specialized rifle grenades like the SIMON breach grenade. Breaching using explosives is primarily an operation performed by highly trained explosives experts, such as combat engineers. Explosive breaching charges can range from highly focused methods, such as detcord, plastic explosives, or strip shaped charges that explosively cut through doors or latches, to large satchel charges, containing 20 pounds (9 kg) of C-4, that can breach even reinforced concrete bunkers.

Mechanical Breaching

A Halligan tool and an axe, both common tools used by firefighters to breach doors to fight a fire

Mechanical breaching can be minimally destructive, through the use of lock picks. This method is relatively slow and requires a trained operator, but does not damage the lock or door. More dynamic methods use force to break the lock or door. The common methods are to use a lever, such as a Halligan bar or crowbar, or to use a tool to concentrate a large amount of force on the door, such as a sledgehammer, hydraulic jack, or battering ram.

Ballistic Breaching

Suggested target locations for breaching a door at the latch (left) and the hinges (right). Ballistic breaching uses a projectile weapon to breach an opening. In some military applications, weapons used can range from the 120mm cannon of a main battle tank with a HEAT round, which will breach most obstacles easily, though the force involved may be far beyond the rules of engagement.A less damaging ballistic breach needs to destroy either the latch and lock, or the hinges of the door, and the ideal choice for this is the shotgun. While in theory other firearms can be used, handguns are underpowered and rifles are less effective than the shotgun and pose a far higher risk of ricochet and collateral injury. Most shotgun ammunition can be used for breaching, though the risk of injury varies with type. Of the available shotgun ammunition, shotgun slugs pose the highest risk, as they will retain significant energy to cause lethal wounds well after they have penetrated the door. Buckshot is far safer, and birdshot even safer, as the multiple small projectiles disperse quickly after penetration, reducing the chances of causing a lethal wound. The safest option is a frangible round such as the Hatton round, which turns to dust upon penetrating the door, and disperses completely upon exit.
Attacking the latch and lock is easiest, as it requires fewer shots and is easiest to target, whereas attacking the hinges requires more shots, and the hinges may be hidden from the outside. Shots to the lock side should be fired at a point halfway between the lock or handle and the door frame, in order to dislodge the bolt holding the door shut. According to US urban warfare doctrine, the operator of the breaching shotgun should place the muzzle in contact with the door, or as close as possible, and fire downwards at a 45 degree angle to minimize risk to occupants of the room being breached. Two shots should be fired, and then the door kicked, pushed, or pulled open. If the first two shots fail to breach the door, then the process should be repeated. If the ballistic breaching is not sufficient, then mechanical means should be used to finish the breach. If the hinges must be breached, then the US urban warfare doctrine calls for three shots per hinge followed by a kick or pull on the door to open it.

Shotgun Breaching

A breaching round is a shotgun shell specially made for the purposes of door breaching. It is typically fired at a range of 6 inches (15 cm) or less, aimed at the hinges or the area between the doorknob and lock and door jamb, and is designed to destroy the object it hits and then disperse into a relatively harmless powder.[1] [edit] Design and construction Breaching rounds are designed to destroy the locking mechanisms of doors without the risk of ricochet. These rounds are typically 12 gauge, frangible shotgun slugs made of compressed or sintered metal powder in a binder. Example of breaching rounds are: The US Military M1030 breaching round, a 12 gauge 2 3/4 inch (70 mm) shell which uses a 1.4 ounce (40 g) projectile made of powdered steel, bound with wax[2][3] The Clucas MoE Hatton Round, a 12 gauge 3 inch (76mm) magnum shell which uses a 50 gram (1.8 ounce) frangible projectile, consisting of a high density material in a plastic binder[4] When fired, the full force of the round is delivered to the target, minimizing the risk of injury to persons behind the door being opened. If fired directly at a human target, they can cause lethal injury.