The deceptively massive Type 97 anti-tank rifle
You occasionally see images of the Kokura Arsenal-made Japanese Type 97 (semi) automatic cannon, a gas-operated, open-bolt (!) 20mm anti-tank weapon, floating around, circa 1935-45.
A rare Japanese Type 97 anti-tank rifle captured on Guadalcanal from the Ichiki Detachment
Japanese Type 97 anti-tank rifle
U.S. soldiers with a captured 20mm Type 97 Japanese anti-tank rifle at Hollandia, 1944
Soviet soldier inspecting a captured Japanese Type 97 20mm anti-tank rifle in Manchuria in 1939, note five spare magazines. The front and rear carrying handles allow four men to carry it like a stretcher.
And, naturally, you think it is akin to similar beasts seen in the West during the same time period, such as the 28-pound German Panzerbüchse 39, the 36-pound .55 caliber Boys anti-tank rifle, and the 38-pound 14.5mm Russian Degtyaryov PTRD-41, each of which could be carried and used by a single operator in a pinch, with an optional assistant gunner always welcome.
Two-man Soviet anti-tank teams on Shumshu Island during the Kuril landing operation. August 1945. While the Degtyaryov PTRD-41 (shown) and Simonov PTRS-41 14.5x114mm anti-tank rifles were hopelessly obsolete by 1942 on the Eastern Front, they could still penetrate 30mm of steel armor at 500 meters, which was more than enough for Japanese Type 97 Chi-Ha/Shinimoto and Type 95 Ha-Go tanks arrayed against them in the Kuriles which boasted 25mm and 12mm, respectively, along their toughest parts.
The Boys rifle could be, and often was, a single-man carry in the field
Then you find out that the Type 97 weighed 115 pounds unloaded, growing to over 140 when its full 7-round magazine and optional armored shield were attached. This was even heavier than the Lahti L-39 (109 pounds) or the Swiss Solothurn S-18/100 (99 pounds), and it had a TOE that gave it an 11-man crew, including nine horses.
Oof.