Your results are reason enough for every 3861 owner . . .
. . . to participate in this timing survey. And what's most astonishing is that there's purportedly little in the way of human intervention with this caliber compared to the chronometers that made Omega famous.
The chronometer calibers revered by vintage aficionados required extensive bench time before casing. My understanding is there's little in the way of hands-on regulation with current co-axial escapement movements.
That's what makes them so remarkable.