Different 9mm pistols through history with aluminum alloy frames tended to crack with a steady diet of "heavy" ammo use, meaning 124gr NATO, +P or heavier. I put around 6,000 rounds of CDN 9mmNATO through a S&W M459 with no cracks I could see before I sold it. There were several members who had their M59's around the same time all fail between 5,000 and 6,000 IIRC. Maybe it was 10,000 too long ago to remember. If the 459 was superior I'm not really sure but S&W immediately replaced the frames on the older M59's at no charge though. If my 2012 Nork NP-22 cracks at 5,000, I'm not sure if I'll see a free frame. Weren't there P226 frame issues from the mud rails?