and the increasingly modernised ARVN. Homemade or improvised firearms The Błyskawica (Lightning) was a simple submachine gun produced by the Armia Krajowa, or Home Army, a Polish resistance movement fighting the Germans in occupied Poland. It was produced in underground workshops. Its main feature was its simplicity, so that the weapon could be made even in small workshops, by inexperienced engineers. It used threaded pipes for simplicity. In some cases, guerrillas have used improvised, repurposed firearms. One example is described by Che Guevara in his book Guerrilla Warfare. Called the "M-16", it consists of a 16 gauge sawed-off shotgun provided with a bipod to hold the barrel at a 45-degree angle. This was loaded with a blank cartridge formed by removing the shot from a standard shot shell, followed by a wooden rod with a Molotov cocktail attached to the front. This formed an improvised mortar capable of firing the incendiary device accurately out to a range of 100 meters. Flare guns have also been converted to firearms. This may be accomplished by replacing the (often plastic) barrel of the flare gun with a metal pipe strong enough to chamber a shotgun shell, or by inserting a smaller bore barrel into the existing barrel (such as with a caliber conversion sleeve) to chamber a firearm cartridge, such as a .22 Long Rifle. Sanitised arms The Yugoslavian Zastava M48BO (for bez oznake, 'without markings') rifle was manufactured with no markings save for a serial number. These were made in Yugoslavia for delivery to Egypt prior to the Suez Crisis of 1956. Yugoslavia was technically a neutral country, and by sanitizing the rifles sold to the Egyptians, it hoped to distance itself from the conflict between Egypt and Israel. Only a few hundred of the few thousand made were delivered to Egypt, the rest remaining in storage in Yugoslavia until recently rediscovered. They are currently being sold to civilian collectors. Plausible deniability In the present day plausible deniability allows the supply of arms by governments to insurgents without the need for over elaborate ruses. For example, the sheer number of AKM (an upgraded version of the AK-47 rifle) manufacturers and users in the world means that governments can supply these weapons to insurgents with plausible deniability as to exactly from where and from whom the guns were acquired. Improvised explosive devices An improvised explosive device (IED), also known as a roadside bomb,