Interesting article about the .45 Flattops convertibles note he tested at least one .45acp+p load.
https://americanhandgunner.com/our-experts/lipseys-45-convertible/
Typical great article by the Late, Great John Taffin. I know he performed exhaustive tests on the Rugers and pushed the limits occasionally as he was wont to do. He has not been the only one to do so. He and the other writers are entitled to their experienced observations. I offer no criticism. :)