Sunday, January 20, 2008

Mini Guns

Hollywood Miniguns: Predator vs. common sense.

"Hollywood Minigun" from the Predator movie a still image from the PREDATOR movie, featuring the Minigun
In the year 1987 the movie "Predator" (starring A. Schwarznegger) hit the screens. One of the most impressive scenes was the one where the US Commandos, led by "Dutch" (Schwarznegger), attempted to fight back the alien Predator. One of Commandos was armed with the distinctive weapon, a 6-barreled rotary Minigun, fed from backpack ammo box. This gave the impression that the Miniguns can be used for infantry support. It must be noted, that in this movie a special, blank firing version of the Minigun was sued. The electric motor was powered via cable, hidden in the actor's pants, and the actor had to carry bulletproof vest and protective mask to avoid injuries from the fast and violently ejecting empty cases. Had this gun being fired using real ammunition, the actor would ended lying on his back, being forced off the legs by the violent recoil. The "backpack" ammo capacity, also, could be worth only several seconds of fire. lets calculate: 2 000 rounds of 5.56mm ammo will weight about 25 kg (55 lbs); 2 000 rounds of 7.62mm will weight about 2 times more, making such load almost impossible to carry on foots. yet this load of ammo will worth only 20 or so seconds of fire. Add some powerful batteries to power electrical drive of about 4KWt (4+ horse-power), and the bulk of the gun itself, and you'll see that even the strongest man won't be able to carry this load, less to fire it with any chance to hit, due to extremely powerful recoil.

M4a1

Caliber: 5.56mm NATO
Action: Gas operated, rotating bolt
Overall length: 838 mm (stock extended); 757 mm (stock fully collapsed)
Barrel length: 370 mm
Weight: 2.52 kg without magazine; 3.0 kg with magazine loaded with 30 rounds
Rate of fire: 700 - 950 rounds per minute
Maximum effective range: 360 m

FN P90

Caliber: 5.7x28mm SS190
Weight: 2.54 kg empty; 3 kg loaded with magazine with 50 rounds
Length: 500 mm
Barrel length: 263 mm
Rate of fire: 900 rounds per minute
Magazine capacity: 50 rounds
Effective range: 200 meters

The FN P90 submachine gun (SMG) was developed in the late 1980s as a personal defense weapon for the troops whose primary activities does not include small arms, such as vehicle and tank crew members, artillery crews etc. Standard pistols and submachine guns chambered for pistol rounds were proved ineffective against enemy soldiers, wearing body armor; Therefore FN designers first developed a new round with enhanced penetration, initially known as SS90. To achieve necessary high penetration while keeping recoil impulse low, FN used a small-bore approach, creating a round that looked much like the scaled down 5,56NATO round. It must be noted that similar concepts were tried in other countries, most notably in USA, several decades before FN; for example, US Army tested M1 carbines chambered for .221 Johnson Spitfire round back in late 1950s; later on, Colt produced its .22 SCAMP and 5,6x30 MARS ammunition for special SCAMP machine pistol and MARS "mini assault rifle" (a scaled-down M16 rifle) respectively. It must be noted that 5,6x30 MARS round was in a sense a direct predecessor to 5,7x28 FN SS90 round, although the latter featured slightly lighter and faster bullet. By late 1980s a concept of a small-bore, low-impulse "personal defense weapon" (PDW) with good accuracy and lethality at ranges of up to 200-250 meters was well established, although there were no weapons adopted for service yet. FN decided to follow this concept and to create its own PDW using clean sheet approach. Basic ideas used for this development, designated as "Project 9.0", included the following: minimal size and weight of weapon; large magazine capacity; complete ambidexterity; ease of use and maintenance.
To save on size and weight, FN designers put new weapon into compact and lightweight stock of bullpup layout, made of impact-resistant polymer. The high-capacity magazine also was made from semi-translucent polymer, and holds 50 rounds in two rows. To made loaded weapon as compact as possible, FN designers followed the idea of American designer Hall, and placed the magazine above the barrels, with cartridges stored in horizontal position with bullets pointing to the left. While Hall system employed a rotary feed unit, operated by the bolt, to put new cartridge in line with the barrel, FN designers incorporated a stationary helical ramp into each magazine, which rotates cartridge for 90 degrees prior to placing it into feed lips. Complete ambidexterity was achieved by using ambidextrous controls (including dual charging handles and dual back-up open sights), and bottom ejection. Finally, simplicity of aiming was achieved by use of integral reflex type collimating sight and integral laser aiming module (LAM).
Resulting weapon appeared in around 1990 as FN P90 personal defense weapon, along with improved 5,7x28 SS190 ammunition, which replaced polymer-cored bullets with heavier dual-core (steel / aluminum) bullets with better penetration against body armor. Several other types of ammunition were developed for this weapon, including tracer, subsonic ball and soft-core training ball.
First sales of P90 were made to Saudi Arabia in early 1990s; today it is believed that FN sold more than 20 000 of P90's to a wide variety of law enforcement agencies and military special operation units worldwide, including US Secret Service, Austrian Army rangers, Dutch BBE special operations forces, Belgian Army and others. Most interesting fact about adoption of P90 is that so far it has been adopted for the role, directly opposite to its original niche of "personal defense weapon". In fact, most services and agencies that adopted P90 use it for offensive roles, as a specialist or even a primary weapon for various assault teams, and other "professional small-arms users", as opposed to military personnel which primary functions do not include use of small arms.
In around 1995 FN supplemented the P90 with pistol, firing the same 5,7x28 ammunition, designated as FN Five-seveN. Recently, FN also introduced a civilian version of P90, designated as PS90 carbine. This is a self-loading weapon with longer barrel (408 mm / 16").

FN P90 personal defense weapon is blowback operated, selective-fired weapon which fires from closed bolt. The firing is controlled by a removable trigger unit with conventional hammer. A manual safety is located directly below the trigger. Magazine lies at the top of the weapon, feeding from front-to-back, with spiral ramp built into the "rear" part of the magazine. Spent cartridges are ejected straight down through the chute, which exits just behind the pistol grip. The standard sighting equipment includes a non-magnifying collimating sight with "ring and dot" illuminated aiming reticule. Back-up open sights are provided at either side of the primary collimating sight. The so-called P90 USG version is provided with two additional Picatinny rails at either side of the collimating sight base; FN also offers a version with no standard sighting equipment; user has to make its own choice of day and/or night sights and additional equipment, which can be installed on three Picatinny rails - top, left and right. This version is designated as P90 TR (triple rail). The front part of the forward handgrip on P90 is shaped as hand protector, and it can contain integral laser aiming module, which sends either visible or IR laser beam to mark the intended target. For special missions P90 can be fitted with a special silencer, which is used in conjunction with special subsonic ammunition.

UMP 45


Caliber: .45ACP, .40SW and 9x19mm Luger/Para
Weight: 2.1 - 2.2 kg empty
Lenght (stock closed/open): 450 / 600 mm
Barrel lenght: 200 mm
Rate of fire: 600 - 700 rounds per minute
Magazine capacity: 10, 25, 30 rounds
Effective range: 100 meters

The UMP (Universal Machinen-Pistole = Universal Submachine Gun) had been developed by the Heckler & Koch company of Germany in the mid- to late- 1990s and first appeared on the markets in 1999. The key idea behind the UMP was to ceate lightweight and powerful submachine gun, that also will be cheaper than one of the J&K's flagships, the MP-5. UMP, being targeted primary for USA law enforcement market, first appeared in .45ACP and .40SW chamberings, and later - in 9mm.

The UMP is a blowback-operated select-fire submachine gun, being fired from the closed bolt. The receiver is made from the polymer, the controls are fully ambidextrous. UMP can be fired in full-auto, in single shots, and in 2 or 3 round bursts (optional). UMP also has bolt hold-open device, which traps the bolt in the open position when the last round from magazine had been fired. UMP has side-folding buttstock and two set of picatinny rails - one on the top of the receiver, and the other - on the forend. These rails can accept wide variety of sighting and other equipment, such as red-dot sights, laser pointers, tactical grips and flashlights. The barrel has quick mount for snap-on silencer.

Bennelli M3 Super 90


Type: selective pump-action or semi-auto recoil inertia operated
Gauge: 12
Length: 1040-1200mm
Barrel length: 500-660 mm.
Weight 3.2-3.5 kg
Capacity: 8 rounds in underbarrel tube magazine

The Benelli M3 is an updated version of the Benelli M1 shotgun. M3 uses same inertia recoil semi-automatic system as earlier Benelli M1, but with addition of the another Benelli patented feature, which allows to the shooter to lock the semi-automatic action and switch to the manually operated pump-action mode and back in the matter of seconds. The action type switch is located at the forward end of the forearm, and is formed as an annular knurled ring. Rotation of this ring either engages the action rods of the pump system and locks the semi-automatic recoil system, or disengages the action bars, locks the forearm and allows the inertia recoil system to operate the action automatically. This greatly improves the versatility of the shotgun, allowing it to fire low-powered ammunition (mostly of special purpose, such as less-lethal rubber or tear-gas projectiles) in the manually operated pump action mode, and to fire full power combat loads with slugs or buckshot in rapid semi-automatic mode. Underbarrel tubular magazine usually holds 8 rounds for police or military versions, or less in some civilian models.

M3 Super 90 is available with various barrel lengths and stock options, with fixed butt and semi-pistol or pistol grips, or with top-folding butts and pistol grips. Sight options include shotgun-type open sights, rifle type open sights, ghost ring (diopter) sights and various mounts for red dot or low magnification telescope sights and tactical flashlights and laser pointers.

M3 is a high quality, very versatile shotgun, and is very popular as a police weapon, and as a civilian weapon for self defense and sporting purposes (IPSC shotgun).