New poster here. Thanks for all the info in this forum. My new MK9 (with approx 600 rds through it) randomly stove-pipes spent cartridges with all types of ammo. (Probably, 5-6 per 100 rounds). Following instructions on this site, I removed slide numerous times and cleaned and lubed recoil spring assembly, barrel and underside of slide. Whether using 6 rd magazine or 7, it makes no difference. Don't believe that limp wristing is the culprit. Any thoughts or suggestions?