User:Autistic Hyperfixation/Sampo L-41

The Sampo L-41 is an air-cooled, belt fed light machine gun developed by Finnish weapon designer Aimo Lahti

Development History
Experience learned from the Winter War and Continuation War showed that the Finnish Army's Maxim machine guns were outdated, clunky and much too bulky for the modern battlefield. In addition to that fact, the bullet used in the Maxim (Flanged 7.62×53R) was inconvenient for used in a machine gun.

When developing of a new machine gun began many changes were made to the general design, along with smaller things like the use of a metal ammunition belt instead of the cloth belts used in the Maxim and shortening of the length of the belt by 50 rounds (200 instead of 250).

Many aspects of the Maxim were retained in the new design however, such as the feeding mechanism. The feeding mechanism was still "Maxim Style" with the cartridge first being pulled back from the belt, lifted to the same level as the barrel and finally fed into the chamber. Because of this the feeding mechanism on the new machine gun was quite complex and somewhat heavy.

At the front end of the gas piston there was a regulator tool that was used for adjusting the rate of fire of the weapon (between 600 and 800 Rpm).

The sights on the new machine gun were based on the M/39 Ukko-Pekka rifle, with the rear sight sitting on top of the lock frame and the front sight sitting above the throttle cylinder. Serial production versions of the new machinegun were simplified in shape, had a shorter barrel, and included a keyway on the lock frame for mounting a separate sight.

Production and Experimentation:
The first prototypes of the weapon were completed in autumn 1941 by Valtion Kivääritehdas (VKT). After test firing, the first set of 50 guns was ordered. 26 guns were produced which were test-fired in July 1942, however due to poor material (soft closing surfaces) the guns were returned to VKT for repair.

On September 16th, 1942, the weapons were put through an introductory inspection and were then subsequently distributed for front-line use. Later nine more guns would be produced and were subsequently distributed for front-line use as well. The guns served until the end of the war in frontline units. In total, 35 Units were produced.

Early into 1943 the follow defects were noticed in the weapons and munitions


 * Poor quality ammunition would cause the weapon to malfunction;
 * Locks and Recoil Springs would break;
 * Quick heating of the barrel through rapid fire, and the adverse effects on weapon handling;
 * The stand (bipod) was difficult to install on the weapon and awkward to use due to being very light weight.

Sources:

 * Puolustusvoimat, Sotamuseo, Helsinki
 * Palokangas, Markku: Kehitys pikakivääristä kevyeen konekivääriin
 * Palokangas, Markku: Vapaussodan konetuliaseet
 * Palokangas, Markku: Sotilaskäsiaseet Suomessa 1918-1988 osa II ja III
 * Sotatieteen laitos: Talvisodan historia 1
 * Erjola, Risto: Asetuotanto Suomessa toisen maailman sodan aikana
 * Harvila, Lauri: Suomen armeijan käyttämät aseet
 * Timo Hyytinen: Arma Fennica 2 Sotilasaseet, Gummerus, Jyväskylä, 1987

References:

 * Timo Hyytinen: ”Sampo L-41”, Aimo Lahden asekeksinnöt. Jyväskylä: Arma Fennica, 2013.
 * http://www.jaegerplatoon.net/ALMOST1.htm