Editing Shaped charge (section)

===Explosively formed penetrator===
{{Main|Explosively formed penetrator}}

[[File:explosively formed penetrator.gif|thumb|upright=1.4|The formation of an EFP warhead. [[United States Air Force|USAF]] Research Laboratory]]

The explosively formed penetrator (EFP) is also known as the self-forging fragment (SFF), explosively formed projectile (EFP), self-forging projectile (SEFOP), plate charge, and [[Misnay-Schardin effect|Misnay-Schardin]] (MS) charge. An EFP uses the action of the explosive's detonation wave (and to a lesser extent the propulsive effect of its detonation products) to project and deform a plate or dish of ductile metal (such as copper, iron, or tantalum) into a compact high-velocity projectile, commonly called the slug. This slug is projected toward the target at about two kilometers per second. The chief advantage of the EFP over a conventional (e.g., conical) shaped charge is its effectiveness at very great standoffs, equal to hundreds of times the charge's diameter (perhaps a hundred meters for a practical device).

The EFP is relatively unaffected by first-generation [[reactive armor]] and can travel up to perhaps 1000 charge diameters (CD)s before its velocity becomes ineffective at penetrating armor due to aerodynamic drag, or successfully hitting the target becomes a problem. The impact of a ball or slug EFP normally causes a large-diameter but relatively shallow hole, of, at most, a couple of CDs. If the EFP perforates the armor, [[spalling]] and extensive behind armor effects (BAE, also called behind armor damage, BAD) will occur. 

The BAE is mainly caused by the high-temperature and high-velocity armor and slug fragments being injected into the interior space and the blast [[overpressure]] caused by this debris. More modern EFP warhead versions, through the use of advanced initiation modes, can also produce long-rods (stretched slugs), multi-slugs and finned rod/slug projectiles. The long-rods are able to penetrate a much greater depth of armor, at some loss to BAE, multi-slugs are better at defeating light or area targets and the finned projectiles are much more accurate.

The use of this warhead type is mainly restricted to lightly armored areas of main battle tanks (MBT) such as the top, belly and rear armored areas. It is well suited for the attack of other less heavily protected armored fighting vehicles (AFV) and in the breaching of material targets (buildings, bunkers, bridge supports, etc.). The newer rod projectiles may be effective against the more heavily armored areas of MBTs. Weapons using the EFP principle have already been used in combat; the "[[Smart bomb|smart]]" submunitions in the [[CBU-97]] [[cluster bomb]] used by the US Air Force and Navy in the 2003 Iraq war employed this principle, and the US Army is reportedly experimenting with precision-guided [[artillery shell]]s under Project [[SADARM]] (Seek And Destroy ARMor). There are also various other projectile (BONUS, DM 642) and rocket submunitions (Motiv-3M, DM 642) and mines (MIFF, TMRP-6) that use EFP principle. Examples of EFP warheads are US patents 5038683<ref>Ernest L.Baker, Pai-Lien Lu, Brian Fuchs and Barry Fishburn(1991)"[http://www.google.com/patents/pdf/High_explosive_assembly_for_projecting_h.pdf?id=2dkbAAAAEBAJ&output=pdf&sig=ACfU3U1uJ8lS6CfmjJo1JKILjvWDC9sCSg High explosive assembly for projecting high velocity long rods]{{dead link|date=June 2024|bot=medic}}{{cbignore|bot=medic}}"</ref> and US6606951.<ref>Arnold S. Klein (2003) "[http://www.google.com/patents/pdf/Bounding_anti_tank_anti_vehicle_weapon.pdf?id=oOoMAAAAEBAJ&output=pdf&sig=ACfU3U3WM4xBQ5f0d23uQdUeF1unjyGE9Q Bounding Anti-tank/Anti-vehicle weapon]{{dead link|date=June 2024|bot=medic}}{{cbignore|bot=medic}}"</ref>