These rather interesting photos come from TEST REPORT FOR THE CLOSE QUARTERS BATTLE PISTOL (CQBP) BID SAMPLES, PHASE II and are of Colt test articles from the CQB Pistol solicitation which was just awarded to Colt yesterday. They depict various frame cracks.
Guns 11, 12, 14 and 15 (1-10 were not fire tested) fired 12,000 rounds before being deadlined due to visible safety-critical cracks found in the slides. Each slide had cracks in the same location, but they varied in size.
One gun had its recoil spring bend enough to bind the slide to the point it no longer could be tested, it was withdrawn from testing.