The knock on the Remington 10 and 29 is that they are more difficult to repair when they do malfunction, not that they are more likely to malfunction than other pump guns of that era. Parts are said to be hard to find, and difficult to install so that the gun will be properly timed.
I own two well-used M10s and they've given me no problem, but I don't use them all that hard, either.
