COOLING BARREL.
To reduce wear of rifling, the barrel should be kept cool if circumstances allow.
Water is not harmful, and when available may be copiously applied to barrel by means of a sponge or rag.
A hot barrel may be dipped in water, but all traces of latter must be removed from barrel bore and gas cylinder, by blowing through same, by means of cleaning rod, or by firing two or three loose cartridges.
Until all water is blown out of gas cylinder, the gas pressure may be insufficient for ensuring automatic action.