My routine in IHMSA silhouette was to check revolver screws after 40 shots----the standard match. (With, as Flatgate says, the proper flat ground screwdriver.) During an 80 round championship, I checked the screws after 40 shots, again after the 80. (As a side note, I greased the locking lugs of a Remington XP-100 after 40 shots; thus, twice in an 80 round match. While the Remington may be the strongest bolt action out there, it is soft enough to gall easily.)
Side benefit: checking screws helps push DOUBT out of my pea brain.
Remember, the speed of sound through steel is somewhere on the order 14,000 to 16,000 feet per second. Stands to reason heavy recoil and vibration work together to loosen things up.
In designing the New Model single action lockwork, Bill Ruger replaced the hammer/trigger/cylinder-latch screws with pins, even combining the trigger and latch on the same pin. In designing the Security-Six and Redhawk, Ruger took advantage of the lost wax casting process to eliminate the sideplate----and its screws.
Today, the single action children of Sam Colt's 1836 Paterson maintain a tradition of compact-for-power simplicity which, however Old School, is never obsolete. That truth extends to the grip frame and ejector, held on by screws.
David Bradshaw