  We study a series of X-ray-bright, rapidly-evolving active-region coronal
jets outside the leading sunspot of AR 12259, using Hinode/XRT, SDO/AIA and
HMI, and IRIS data. The detailed evolution of such rapidly evolving "violent"
jets remained a mystery after our previous investigation of active region jets
(Sterling et al. 2016, Paper 1). The jets we investigate here erupt from three
localized subregions, each containing a rapidly evolving (positive)
minority-polarity magnetic-flux patch bathed in a (majority) negative-polarity
magnetic-flux background. At least several of the jets begin with eruptions of
what appear to be thin (thickness <~2") miniature-filament (minifilament)
"strands" from a magnetic neutral line where magnetic flux cancelation is
ongoing, consistent with the magnetic configuration presented for coronal-hole
jets in Sterling et al. (2015). Some jets strands are difficult/impossible to
detect, perhaps due to, e.g. their thinness, obscuration by surrounding bright
or dark features, or the absence of erupting cool-material minifilaments in
those jets. Tracing in detail the flux evolution in one of the subregions, we
find bursts of strong jetting occurring only during times of strong flux
cancelation. Averaged over seven jetting episodes, the cancelation rate was
~1.5x10^19 Mx/hr. An average flux of ~5x10^18 Mx canceled prior to each
episode, arguably building up ~10^28 - 10^29 ergs of free magnetic energy per
jet. From these and previous observations, we infer that flux cancelation is
the fundamental process responsible for the pre-eruption buildup and triggering
of at least many jets in active regions, quiet regions, and coronal holes.
