With .357s it is mine. With .38 Spl. +P maybe double that interval, but with Q4070 ammo they won't go 5000 without an armorer touching them.
You can also ask anyone who worked the FBI gun vault at Quantico back then, the APG inspectors who ran the lot acceptance tests for Customs and Border Patrol and the instructors and gunsmiths at FLETC.
If you re-read the revised OP I have incorporated additional comments from the Test Director for US Customs and Border Patrol on their experience, and statements from the contracting agency''s technical representative from Aberdeen Proving Ground.