We have had them running as range pistols since they became available, we have at least 20,000rds through one of our Glock 17 Gen 4 pistols, and have experienced no major issues or malfunctions. We have other Glock 17 pistols that have fired 80,000-100,000 rds and have been retired, two pistols had left rear rails break right off - but still continued to function. All of our range pistols are only run on factory ammunition, last year we obtained almost 50,000rds of Winchester Ranger 124gr NATO Ball and the Glocks run better with the higher pressure ammunition, we will run everything that is available commerically 115gr/124gr/147gr.