German 75-mm Recoilless Gun, LG 40, WWII Tactical and Technical Trends, No. 26, June 3, 1943 (Lone Sentry) (original) (raw)

| The following report on the German LG 40 75-mm recoilless gun (7.5-cm Leichtgeschütz 40) appeared in Tactical and Technical Trends, No. 26, June 3, 1943. [DISCLAIMER: The following text is taken from the U.S. War Department publication Tactical and Technical Trends. As with all wartime intelligence information, data may be incomplete or inaccurate. No attempt has been made to update or correct the text. Any views or opinions expressed do not necessarily represent those of the website.] | | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | |

| GERMAN 75-MM RECOILLESS GUN, LG 40* This weapon is a short-rifled howitzer without a recoil or counter-recoil system, mounted on a light aluminum alloy carriage. A funneled (Venturi) tube is attached to the rear of the bored breechblock; its function is to allow the gases to disperse to the rear, thus eliminating a recoil mechanism. The firing mechanism is seated in a cone-shaped receptacle and centered in the breechblock by vertical struts. The weight of the complete gun is reduced to a minimum by using hollow machined parts, plastic washers, tubular carriage, and aluminum alloy body. Because of the weight of the complete piece, it lends itself to use by airborne troops. The general characteristics of the gun are: Date of manufacture 1942 Caliber75 mm Weight Complete325 lbs Barrel98 lbs Carriage63 lbs Wheels and axles36 lbs Breechblock and Venturi tube 66 lbs Breech ring62 lbs Length of gun (over-all)45 in Length of barrel29 1/2 in Rifling28 lands and grooves -uniform right-hand twist;one turn in 19 calibers Maximum range**3-4,000 yds Rate of fire**12-15 rpm Muzzle velocity? Sights**Cross-leveling gear, andstraight tube telescope Ammunition**HE and hollow charge TubeMonobloc Elevation42°-20° Traverse60°-360° CarriagePlatform or tripod type;detachable wheels for transport Tactical useAT and antipersonnel a. Barrel The tube is of monobloc steel construction. On the breech end, interrupted collars provide for attachment of the tube to the breech rings. It is also machined to seat the extractor and the barrel lock. Externally and midway on the barrel, a steel band is clamped. Its purpose is to lock the barrel and the front leg of the tripod in transport. b. Breech Ring This part of the gun is recessed to receive the barrel and breechblock. It contains borings for the extractor pin, breech-lever mechanism, "safe and fire" lever as well as the barrel lock. The trunnions for mounting it to the carriage and the elevating rack are also attached to the breech ring. c. Breechblock The breech is of the horizontal sliding block type. It is bored to receive the firing housing and firing lever. The firing housing, which acts as a diffuser for gases escaping to the rear, is screwed at the rear to secure the funnel-shaped "Venturi" tube. The breech mechanism lever performs a double function. It operates the breechblock and also cocks the piece when the lever is depressed. d. Venturi Tube This funnel-shaped tube is screwed on to the rear of the breechblock. Its purpose is to disperse the gases to the rear, eliminating recoil. e. Carriage The top carriage or body is constructed of an aluminum alloy, formed with a circular base. It contains borings for the elevating and traversing mechanisms and lock, as well as the trunnion caps for seating the trunnions. The gun can be traversed 360° by locking the elevating mechanism, but its ordinary traverse is 60°. Elevation is limited to 42° by stops, but the rack can be locked at 20°. At the right side is a bracket for attaching a small spare-parts box. f. Lower Carriage or Platform The lower carriage consists of the wheels, platform, three tubular legs, tubular guide rails, tubular axletree, base ring traversing rack, and stub axles.The wheels are light-weight metal disks fitted with solid rubber tires and can be quickly detached from the axletree.The three tripod legs are pivoted in lugs on the base ring. The front leg can be placed in one of two positions for firing by engaging it in a slot in the center of the axletree. The left and right legs can be placed in two positions by locking them in slots of the guide rail. The three tripod legs have small spades for steadying the gun while firing. Remarks: The method of firing the piece and the types of cartridges, propellants, and projectiles are, and will be, unknown until they are secured. Many theories have been suggested by observers, but until the projectile is received and fired it remains pure conjecture. No detailed information is available at present concerning the sighting equipment, because the captured weapon arrived in the U.S. without sights of any kind. There is a sight bracket attached to the left side of the carriage.*Extracted from a recent Aberdeen Proving Ground report.**From a British report. | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | |