Machine guns were typically manned by up to six men, a sniper could take one out but another would soon take their place and the sniper would have to continue doing this without somehow being shot in return. Additionally, First World War offensives were preceded by artillery barrages intended to neutralise German defenders, this includes the riflemen that also inhabited the trenches. Artillery was also required to cut the deep belts of seabed wire erected in front of the trenches. What this means is that although in theory a sniper could have been used to neutralise a machine gunner, the amount of dust, smoke and other particulate launched into the air by the artillery would most likely have completely removed the ability for any sniper to accurately locate and target an individual machine gunner.