Here's a quote from Massad Ayoob's "Greatest Handguns of the World":

"Back in the '70s, a Colt executive confirmed what contemporary gun writer Jac Weller had written: they had indeed bored out Detective Specials to .357 Magnum and found that they'd go 5,000 rounds without a problem. They just hadn't produced the gun because they didn't think anyone could handle the brutal recoil back then."

Tough little gun, one of my very favorites. But I think I'll stick with .38 Special. :-)