DO NOT BUY A KEL-TEC P40!
Regardless of what Kel-Tec and the zealots on KTOG say, the P40 did not work. It has serious reliability and safety issues, the most serious of which was bullet setback. When the pistol stripped the round from the magazine it would slam into the base of the feed ramp forcing the bullet back into the case and causing a "smile" shape on the nose of the bullet. Usually it would jam against the feed ramp, but sometime it would feed. I had a P40 that had this problem. I was far from alone, as the KTOG forum was alive with complaints about the same problem with P40s. All the zealots over there seem to have "forgotten" this serious safety issue now.
My P40 went back to KT three different times to correct the problem with the "smile". KT shipped the gun back to me three times telling me it was fixed. It never was. It became less and less feed reliable each time they cut some more metal off the feed ramp, but it never fixed the "smile" and bullet setback problem. Each time they sent it back to me, they claimed it was fixed. They lied, pure and simple. Anyone who actually shot this gun after "fixing" it would have seen the same problem I saw when it got back to me. So, I spent a small fortune shipping the thing back to them, and they never corrected the problem or paid for my shipping costs. So much for great KT customer service. The gun was also plagued by small parts breakage and other reliability problems.
I know I will catch flak for saying this, the KT zealots are just as nuts, if not more so, for Kel-Tecs as the 1911 and Glock zealots are.
KT makes some decent products, but they have a problem with quality control and the P40 was, as a rule, junk, with some samples working as intended. If you get a KT, get the 9x19mm version, but I'd get the Kahr.