16-239 Garand Picture of the Day - Bougainville 1943

https://www.milsurps.com/images/impo...x_on_Bou-1.jpg

Marines Searches Japanese Pillbox on Bougainville 1943

I don't think you could put enough rounds and grenades through the door to make me comfortable enough to peek in like that.

Until it's blown flat...then there's no door.

Flame thrower if the fire does not kill them the lack of oxygen will