主题：【国民党抗战老兵回忆】消灭日军战车 -- MacArthur

大概查了一下，得到如下的资料http://en.wikipedia.org/wiki/Boyes_Anti-tank_Rifle

A bolt action rifle fed from a 5 shot magazine, the weapon was large and heavy with a bipod at the front and a separate grip below the padded butt. To combat the recoil caused by the large 0.55 inch (14 mm) round, the barrel was mounted on a slide, and a shock absorber was fitted to the bipod along with a muzzle brake on the barrel.

Effective to about 300 yards (300 m) as an anti-tank and anti-vehicle weapon, it was able to penetrate 3/4 in (20 mm) of armour at up to 100 yards (100 m). Its effective range against unarmoured targets (eg infantry), was much further. Although useful against the early tanks, the increases in vehicle armour during WW2 left it largely ineffective for anti-tank duties and it was replaced in service by the PIAT anti-tank weapon. It still saw some use against bunkers, machine gun nests, and lighter vehicles. In the Western Desert the large bullet could throw up splinters from rocks to cause casualties and it continued to be used in the Pacific theatre against Japanese tanks; the Japanese did not replace their older lightly armoured tanks, spread out across the Pacific and South East Asia, with newer ones until later in the war. The weapon had been designed with these lighter tanks in mind.

似乎有效射程为300M，在100M距离上可击穿20MM装甲。

但原文里的老人也是又记错的可能，毕竟半个多世纪了。

为老大的眼力喝彩，上花！