TCD MS 10516 folio 38 recto
[14th September 1916] beastly thing. Fourthly come the “cracking bullets”, I do not understand the production of this sound. The noise is that of a small explosion like the firing of a min[i]ature rifle or the loud crack of a whip. Some suggest that they are explosive bullets, others that that they are bullets discharged from small bore rifles, others that they are due to the sound of the bullet in the air and the noise of the explosion by which the bullet was expelled reaching the ear at the same moment. I inclined to the last explanation as I heard these cracking bullets only when within some 400 to 600 yards of the enemy, and this distance, I think, is about that at which these sounds ought simultaneously to arrive. These explosions, when close, are alarming; but, being sudden and lasting for an instant, they do not promote the same instinct to /