I have experienced several issues with revolvers in IHMSA silhouette competition, where it is not uncommon to fire 80-160 rounds of very hot ammunition in the course of a match. The issues have included:
1. Screws backing out on my S&W M29 and M629; both frame and cylinder-retention screws.
2. Base-pin's escaping from Ruger Super Blackhawk 44 Magnums and .357 Maximums (easily solved by a Belt Mountain replacement pin and an extra-power retaining spring).
3. Rear sight pin drift on Ruger single actions (endemic across all Ruger revolvers, and easily solved by keeping an eye on it and pushing the pin back in as needed).
4. Cylinder/Frame binding on S&W M629 no-dash (pre- "Endurance package" engineering change) as the gun got hot in the course of a match.
None of these are "malfunctions" so much as they are indicative of the complexity of revolvers and the need to keep an eye on them, particularly if you're running them hard.
Also, I have found that cleaning the operating surfaces (recoil shield; cylinder face; ejector star; forcing cone; pawl, and hand) of my revolvers between each course of fire (every 40 rounds in IHMSA) makes life much easier; this is especially true of rimfire revolvers and I tend to also brush out the chambers on my S&W M617 between every bank of targets (every 10 rounds) to prevent bullet deformation from excessive seating pressure.