Glock's
I have shot Glock's, Beretta's, and SIG's to failure. The most recent was my G22 at 33,000 rounds, and the slide broke, not the "plastic" frame, for you traditionalist wankers (it still worked too!). My Beretta 96 broke (locking block, surprise) at 12,000, and the SIG had the rails come off and frame crack at an unknown round count (lot's and lot's of 9mm). The difference? The Glock still worked. I have seen several break in service, and I have seen close to a half million rounds minimum of factory.40 down range in the past ten years. The Beretta's failed completely, the Glock's break (pin's, locking block's, slide rails, slide stop levers) but they still work, which is what I would put my money on. Guns are mechanical and they break, ammo is manufactured and it fails sometimes. There is a reason Glock own's 70% of the LE market in North America (G22, actually), it is because they work when they need to.