My S&W Model 19-2 locked up the first time I put a box of magnums through it. These were mild Remington factory loads, nothing special. Between one shot and the next the trigger and cylinder locked up so tight I could barely open the gun. Turns out the gas ring at the front of the cylinder had come loose and was now lodged against the forcing cone. I had to send to back to S&W to get it fixed for a hefty fee.
Now I vastly prefer revolvers, in fact I don't even own a semiauto. But as many have said in this thread before I think the idea that revolvers are more reliable than semiautos is a total myth. I wouldn't trust any revolver to fire 100% if dropped hard on its side, for example. But any quality semiauto should be able to pass that test.