I was introduced to big bore anti-tank (anti-material) rifles back in the 80s when I became an ardent follower of the board game Advanced Squad Leader (ASL was originally produced by the Avalon Hill Game Company, which was purchased by Hasbro, who discontinued production of the game. ASL is now published by MLB pitcher Curt Schilling and his Multi-Man Publishing company.) For those of you unfamiliar with the game, ASL was arguably the most accurate and detailed squad level tactical board game ever developed, with counters representing individual squads, leaders, tanks and support weapons.
Anyway, the one support weapon that caught my eye was the L-39 Lahti 20mm AT rifle. In game terms the Lahti was heavy (5 portage points) and it fired off of the AVF kill table under the 20L column (the only squad portable weapon capable of doing so.) In real life terms the L-39 was heavy, (109 pounds, necessatating its transport by reindeer) and possessed such savage recoil (its cartridge, the 20 mm x 138 mm Solothurn Long, was the largest ever fired by a shoulder fired weapon in the war) that the Finns dubbed it the "Norsupyssy" ("Elephant Gun"), but it was also capable of reaching out 1,000m and penetrating 10mm of armor plate. Rendered obsolete by advanced Soviet tank designs by 1941, the incrediable accuracy of the L-39 enabled it to remain in service as a long range sniper rifle.
Seventy years later, the concept of the long range, big bore, anti-material rifle has come full circle. With .50 caliber (12.7mm) rifles a dime a dozen, my question now is, who fields the new Elephant Gun of the 21st century?
In terms of penetrating capability, the Big Stick designation would seem to go to the Austrian Styer IWS 2000. Firing a propriatary 15.2mm APFSDS (Armor Piercing Fin Stabilized Discarding Sabot) mini tank round, the armor piercing dart will penetrate 40mm of test armor at 1,000m. Unfortunatly, the 40-pound IWS 2000 has yet to enter service with any military (its unique ammunition is a logistical turn-off to most nations.)
As for absolute caliber, the biggest rifle out there is the Barret XM-109 25mm payload rifle. Firing a low-velosity, scaled down version of the 30mm M789 HEDP (High Explosive Dual Purpose) ammunition used by the AH-64 Apache attack helicopter, the XM-109 is capable of penetrating just under 40mm of armor, and, when used with the Barrett Optical Ranging System (BORS) has an effective range of 2,500m. Yet, like the IWS 2000, the 33-pound XM-109 is still in a developmental status (currently the felt recoil of the XM-109 is outside maximum Army tolerances.)
But, if youre looking for something you can take home tonight, the gun for you is the Croatian RT20 20mm rifle. Developed to shoot the thermal sights off of Serbian M-84 (T-72) tanks, the RT20 fires the 20x110mm Hispano-Suiza HS 404 cartridge which can trace its roots back to the 1930s. Marketed as a 20mm hand cannon, the RT20 fires the largest 20mm cartridge of any currently available anti-materiel rifle (most other 20mm rifles are chambered for the Russian 20x99mm R ShVAK round or the German 20x82mm WWII-era MG151 projectile.) To compensate for the rounds enormous kick, the 42-pound single-shot RT20 is equipped with a unique gas-operated recoil compensating blast tube. Operating along the same principles as a recoilless weapon system, this blast tube redirects propellant gasses to the rear of the firer, to reduce felt recoil. Unfortunately, this recoil method also presents a blast hazard for individuals behind the weapon, so care must be taken when firing the RT20 in enclosed spaces.
Of course, the hard part is going to be finding reindeer to pull it...
-- Eric Daniel