I have no idea where that 5000 round figure came from but recall reading about the original tests which resulted in the M1911 being selected.
John Browning personally supervised the building and assembly of the pistols submitted to the Army testing board.
The Colt blew away all the competition, firing 5000 rounds without a single malfunction which had never happened before. Interesting that they used the 5000 round limit back then.
I have a 1911A1 that I’ve put 60,000 rounds through.No jams,and never had any part break.I did replace the 50 year old recoil spring because I though it was getting a little weak,but the old spring was still working OK.