kahr polygonal barrel in a CW380

[CrusaderBill]

Can the kahr polygonal barrel that comes with the PM380 be used in the CW380 model, since they share the same frame? Will this cause any issues?

[CJB]

Yes. No.

No reason to do so though....

[CrusaderBill]

Thanks CJB, but why do you say there is no reason to do so?

[yqtszhj]

The barrel that comes with it is great. No need to swap it out.

[CJB]

Thanks CJB, but why do you say there is no reason to do so?

Because the polygonal barrel has little or no added accuracy, in its own right, and coupled with much more important factors to bullet placement on the target, any miniscule advantage of the polybore is like a drop of sweat in the ocean.

Trigger control. Fit of barrel to slide in the back, and front, and bottom where it contacts the slide stop in. Trigger control. Fit of slide to frame. Trigger control. Sight radius. Trigger control. Ammunition tolerances. And lastly, trigger control.... are all factors in overall bullet placement.

There are some myths to polygonal bores. First is they're a huge expensive thing. They're not. No price difference in theory or practice. They're all made from hammer forged blanks. Process is identical. Only the mandrels are different. Second thing is that they're hugely accurate. Depends on the quality of manufacture, the mandrel, post hammering machine work, metal, stresses... all sorts of crap.

Trust me. In a pistol, zip, nada, no advantage in accuracy.... however....

Poly bores are a major ***** to match to bullets recovered, such as those suspected of being used in crime.

The best rifling is still cut rifling, jury out on the ratio of land to groove, and moderate gain twist is still in fashion and doing well. Almost all winning benchrest rifles use cut rifling made in deep drilled blanks, stress relieved several times and only very lightly honed. Another form of rifling is button rifling, which can be done inexpensively by hydraulically pushing a solid carbide "button" through the bore, ironing the pattern into the metal. This is the worst rifling, producing varied stresses in the finished barrel. But its cheap to do. Hammer forging starts with a short fat blank, which is fit over a mandrel having the shape of the rifling on its exterior, and the hydraulic hammers beat the living piss out of the blank until its long and skinny, and has been formed perfectly to the mandrel (and sometimes the chamber as well). The hammering stress relieves the barrel as part of the forming process.

Manufacturers will speak about "Our highly accurate polyganally rifled barrel" but its double speak. It should be read: "Our barrel is hammer forged, over a polygon mandrel, and as a hammer forged barrel is more accurate, all other things being equal, than a button rifled barrel".

[dsk]

The barrel in a CW380 is slightly longer than a P380, by maybe .10" or so IIRC.

[CrusaderBill]

Thanks again for the great information CJB! :-)