My Gen 4 G19 is at 32,000+ and functioning 100% The pistol had an ejection issue over the first 1300 or so. Brass to face, stovepipes etc I put in an Apex extractor and non-LCI bearing at 1300 and have not had any issues since, except when I put the OEM LCI extractor and bearing back in a few weeks ago. The OEM extractor is crap, and I immediately got BTF when I did that. I threw away the OEM extractor and have put 2000 or so through it since with the Apex, no issues. I change out the recoil spring assembly each 5000 rounds.