Thanks to all for your opinions. I really like the size, appearance and accuracy of the 40P but have had occasional FTF ever since I bought it.
3 days ago I fired it with (a) standard magazine springs (b) a Wolff 20 lb spring with no buffer and the MSC stainless guide rod, cut so it barely protrudes from the end of the frame. (c) I used both magazines which I disassembled, cleaned, lightly lubricated (d) used 2 brands of factory ammunition. Result, no malfunctions in about 50 rounds. For now, hooray.
desertrat23 in Mesa, AZ