Dimensional differences Colt Cobra vs. King Cobra

[Morne]

So...the effort to find a holster for the new Colt King cobra has proven difficult. Apparently, there are no molds readily available to the holster making community. So, what's a wheelgunner to do?

Chatting with one of the holster makers he said that he could just take the mold for the current Cobra and pack some extra barrel length onto it for the King Cobra's longer barrel. That made sense to me, but then I started wondering if barrel length was really the only difference. Having both guns, and a set of digital calipers, I proceeded to measure some dimensions that might matter to how they fit in the holster:

Length from forcing cone to end of barrel shroud = Cobra 2.154"; King Cobra 3.094"
This difference is well known, no big deal.

Cylinder diameter = Cobra 1.398"; King Cobra 1.401"
Cylinder length = Cobra 1.559"; King Cobra 1.559"
That small of a difference in diameter is strictly in the machining tolerance band. Thus, the cylinders are (externally) identical.

Height from bottom of frame window to bottom of trigger guard = Cobra 1.657"; King Cobra 1.663"
These are identical.

Width at the forcing cone = Cobra 0.777"; King Cobra 0.777"
This is the frame maximum width between the forcing cone and the start of the barrel shroud. Again, identical.

Top strap thickness = Cobra 0.186"; King Cobra 0.288"
Top strap width = Cobra 0.599"; King Cobra 0.603"
Now we see an obvious difference. This makes sense for a .38 vs .357. Depending upon how the holster maker forms the sight channel this may or may not matter.

Barrel Shroud width = Cobra 0.619"; King Cobra 0.699"
Height from top of Barrel shroud to bottom of Underlug = Cobra 1.011"; King Cobra 1.145"
Underlug width = Cobra 0.380"; King Cobra 0.460"
These are real differences. The Cobra starts out with a barrel shroud width essentially identical to the King Cobra but rapidly gets stepped down to the listed dimension that is 0.080" thinner.