Has anyone done this, or considered it? My thinking is that the .380 and the 9x18 are close enough (as evidenced by the fact that both Makarov and CZ use the same mags for both calibers) that a Kel-Tec P-3AT barrel could be modified by a competent gunsmith to shoot 9x18. The .380 is a .355, and the 9x18 is .364, so you're talking less than 0.010" difference - I'd expect the barrel to be able to handle that as-is. Cheaper, more available ammo, with quite a bit more punch. I've posted this on the Makarov forum as well, to see if anyone has done it. Thoughts?