Lahti AT Rifle

The Finnish Weapons Series

Lahti m/39 Anti-Tank Rifle



This is my second version of the Lahti Model 39 anti-tank rifle, and the second in my series of Finnish guns. If anyone has additions or comments, please let me know.

Bibliography:

  • -: 20 mm:n panssaritorjuntakivääri L/39. Puolustusvoimain Pääesikunta - Taisteluvälineosasto, Helsinki 1942
  • Palokangas, Markku: Military Small Arms in Finland. Second Volume - Finnish Weapons. Vammalan kirjapaino, Vammala 1991
  • Hogg, Ian A and Weeks, John: Military Small Arms of the 20th Century. Arms & Armour Press, London 1985


    Stats:

    Lahti Model 39 anti-tank rifle
    20 mm ATR
    Mag: 10 box
    Length overall: 88.2 in (224 cm)
    Sight radius: 30.3 in ( 77 cm)
    Barrel length: 51.1 in (130 cm)
    Weight: 109.1 lbs (49.5 kg) unloaded without magazine
    Weight of empty magazine: 7.5 lbs (3.4 kg)
    AP round weight: 0.7 lb (0.337 kg)
    AP bullet weight: 0.3 lb (0.148 kg)
    AP tracer bullet weight: 0.3 lb (0.152 kg)
    Charge weight: 37 g

    Muzzle velocity: 800 mps

    
     Penetration   mm   Degrees   Distance meters    
                  --------------------------------
                   30     90         ?
                   20     60       300
                   16     60       500
       
    
    Lahti Model 39/44 anti-aircraft rifle
    Weight, weapon: 105.8 lbs (48 kg) unloaded
    Weight, mount: 19.8 lbs ( 9 kg)
    Cyclic ROF: 80-100 rpm


    
    Panssarintorjuntakivääri L-39, Ilmatorjuntakivääri L-39/44
     20mm ATR
     Finland
    
     Length: 88.2 (224 cm)
     Weight unloaded: 109.1 lbs (51.4 kg) / 
                      125.7 lbs (57 kg) L-39/44 with AA mount
    
     RT:     18
     ROF:    1/*1 
    
     Cap:    10 box
     AW:     14.9 lbs (6.8 kg)
    
     KD:     60
     SAB:    12
    
     Aim Time: 
               1  -35
               2  -25
               3  -19
               4  -15
               5  -10
               6   -7
               7   -6
               8   -5
               9   -4
              10   -3
              11   -2
              13    0
    
     Ballistic Data:
                 10   20   40   70   100   200   300   400
        *FMJ PEN 54   51   46   40    34    21    13    7.6
              DC 10   10   10   10    10    10    10    10
        *JHP PEN 51   48   63   54    47    29    17    10
              DC 10   10   10   10    10    10    10    10
          AP PEN 78   73   66   57    49    30    18    11
              DC 10   10   10   10    10    10    10    10
    
              MA  .4   .6   1   1.8    2     6     8    10
              BA 63   56   48   41    36    26    21    17
             TOF  0    0    1    2     2     5     7    10
    
    
    The Lahti Model 39 anti-tank rifle was a large, heavy weapon with a rifle stock, pistol grip, an over-the-barrel magazine remiscent of the Bren machine gun) and a long barrel covered with a perforated barrel jacket. The gun had spiked feet or plywood skis on small spring dampeners for balance.

    Nicknamed "the Elephant Gun" by troops on the front, the Lahti ATR had an incredible kick which savaged the shooter. The round produced a maximum pressure of 3000 athmospheres in the barrel and since the only buffering was some padding between the gun's stock and the gunner's shoulder, effect on the shooter was spectacular: his upper body was literally thrown back some six inches (15 cm) by the recoil. Although the gun itself was semi-automatic and therefore immediately ready to fire again, it took time for the shooter to recover from the recoil and this is reflected in the SAB.

    The weapon was issued with various accessories: Spare magazines, covers for various parts of the gun, a carrying pillow, a muzzle-brake cover, a towing line, two toolboxes and a transportation box. Four magazine bags containing two magazines each were provided. The magazines had three holes through which the gunner could estimate how manyrounds he had remaining. Magazines were reloaded using a special loading tool in toolbox number two. A barrel grip made it possible to carry the gun while the barrel was hot and a canvas cover was provided to shield the weapon from the elements while being moved or in position. The carrying pillow could be fastened with two screws onto the bottom of the gun. When the gun was then hoisted onto one's shoulders the pillow made the weight slightly less unbearable.

    The metal muzzle-brake cover was attached with a chain onto the barrel and had to be removed before firing. When the gun was pulled into or out of firing position under enemy observation the towing line was attached onto the ski bipod and some members of the crew would pull the gun forward while others pushed. The skis were strictly for transportation only and were to be removed before firing.
    Toolbox #1 contained spare parts such as springs and other breakables as well as tools and gun oil for cleaning and maintaining the weapon. Toolbox #2 contained more spare parts including parts for the bipod, more tools, a larger oil can and the magazine loading apparatus.

    The crews were instructed to use less grease on the gun when temperatures fell to 20 degrees below zero Celsius (-4 degrees F) and to use no grease at all in -30 degrees C (-22 F). After firing a large number of rounds it was recommended to clean the bolt as soon as possible of accumulated soot as it had a tendency to cause stoppages.

    About 400 of these Aimo Lahti designed weapons were ordered on the eve of World War II. Only two prototypes made it to the Winter War of 1939-40, but over 1800 Lahti ATRs were used in the Continuation War of 1941-44. The Lahti ATR was a capable weapon in 1941 against primitive Soviet armor. However it quickly became obsolete with the introduction of newer tank types such as the T-34 medium tank - though it could always break even the more advanced tanks' tracks. During the trench warfare period of 1942-43 the Lahti ATR was used extensively against bunkers and found to be accurate enough to hit enemies through firing slits. The sights were graduated from 200 to 1400 meters.

    The rifle found a new use around 1943 when the Soviet air arm started to make extensive use of armored ground-attack planes such as the IL-2 Sturmovik. These planes tended to be rather slow-flying but were extremely resistant to small-weapon fire due to their heavy armor. In frustration the standard 20 mm anti-tank rifle was mounted atop tree stumps on makeshift AA mounts. Though Lahti rifles may have been credited with some successes, hitting an airplane with a slow-firing semi-automatic weapon remained problematic. In the summer of 1944 some 300 Lahti Model 39/44 anti-aircraft rifles were produced. This weapon was a full-automatic if still slow-firing version of the ATR with a special mount for tree stumps and large sights better suited for AA work.

    In the beginning of the 1960s Lahti rifles were decidedly outdated for both anti-aircraft and anti-tank work and the Defence Ministry sold over 1000 Lahti rifles along with 200 000 rounds of 20 mm ammunition to gun collectors in the United States. During the Vietnam war it was suddenly realized that helicopters were becoming a factor on the battle field and that Finnish soldiers had little equipment to combat such a threat. The remaining Lahti AA rifles were designated stop-gap anti-helicopter weapons and mothballed until 1988, when they were finally scrapped.





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