Just an update to a previous post. Yesterday one of our guys showed up with a brand new Glock Gen 4 model 23. We cleaned it, oiled it , loaded 3 mags to max with 180 grain FMJ. Commenced shooting...second mag, fifth shot, failure to feed. FMJ! First firearm related malfunction of a Glock on my range with thousands of rounds fired in hundreds of guns. Glock perfection, keep improving it til it stops working.