Cold Bore Shot
The first shot fired from a cold, and often clean, barrel, which can land slightly away from the group produced once the barrel is warm and fouled.
A cold bore shot is the first round fired from a barrel that has cooled to ambient temperature and has not yet been warmed by shooting. For some rifles this first shot prints in a slightly different spot than the rest of the group, since a cool barrel and a settled bedding can shift the point of impact a small but measurable amount. Hunters and field shooters care most about this shot, because in the real world the most important round is usually the first one out of a cold barrel.
The effect is often combined with, but distinct from, the influence of a cold-clean-bore, where a freshly scrubbed barrel lacking fouling adds its own first-round shift. Precision shooters track the cold bore tendency by recording where that first shot lands relative to their established zero and noting it in their dope. Knowing the offset lets a shooter hold or correct for it when the first round truly matters.