The cold bore shot – it’s a phantom many precision rifle shooters acknowledge, yet few rigorously quantify. Is it a true, predictable POI shift, a consequence of barrel harmonics changing as steel heats, or merely the first shot jitters manifesting as an 'excuse' for a flier? For years, the narrative has been split, often anecdotal, leaving many competitors to simply 'account for it' without truly understanding its precise mechanics.
Local squad members Mark 'Doc' Riley, wielding his stalwart BAT TR action, Criterion 6GT barrel, and Kahles 525i optic, alongside Sarah Jensen, running her Defiance Ruckus action, Hawk Hill Custom 6 Dasher barrel, and ZCO 5-27x56, decided to put the theory to the test. Their objective was clear: establish a repeatable protocol to gather hard data on cold bore consistency across multiple rifles and shooters, challenging the common 'it just happens' mentality.
Their method was simple in concept, rigorous in execution. Each shooter would take a single shot at a 100-yard target from a cold barrel, defined as a minimum 30-minute cool-down period. This wasn't about finding a velocity node or chasing single-digit SD; it was about the initial point of impact. They meticulously logged ambient temperature, barrel temperature via an IR thermometer, and POI relative to their established 100-yard zero. This protocol was repeated over three separate range days, accumulating a dataset of 30+ 'cold bore' shots per rifle.
What emerged from the data was less of a consistent 'shift' and more of an increased dispersion relative to subsequent shots. Doc's 6GT, known for its sub-0.25 MOA performance once warm, showed a slight tendency for the cold bore to land 0.1-0.2 MRAD low-left, but with enough variance (up to 0.3 MRAD total spread) to suggest it wasn't a static offset. Sarah's Dasher exhibited similar behavior, albeit with less of a predictable direction, leaning towards a slightly wider group on the first shot rather than a definitive shift. Both shooters maintained their standard match-ready handloads: Hornady 108gr ELD-M in the Dasher, Berger 105gr Hybrid in the GT, both pushed by Varget, carefully optimized for low SD/ES.
The takeaway isn't that the cold bore shot is a myth, but rather that its 'shift' might be less a fixed vector and more an expansion of the shot group’s typical extreme spread. For PRS and NRL competitors, this reinforces the importance of a true cold bore shot on match day – not necessarily as a "sighter" to dial out a fixed shift, but as a critical first data point on conditions and barrel harmonics. It also suggests that extensive dry fire and a solid fundamentals check before the first live round might be more impactful than chasing a mythical, fixed cold bore offset. Truing data remains paramount for dope beyond 100 yards, but understanding the actual *behavior* of that first round out of a cold pipe is crucial for stage planning, particularly on those dreaded 'cold bore first stage' scenarios. The debate over the cold bore will undoubtedly continue, but Riley and Jensen's empirical approach offers valuable insight, reminding us that sometimes, the 'feel' needs to be backed by verifiable impact data to truly refine our edge in competition.
