I had always understood that the alloy J-frames were not rated for plus P but many people reported that they held up fine with limited use. I had a 442 that I used standard pressure Nyclads in, but later bought a 642-1 when that stainless version was introduced. Sometime later, Taurus began to market their small frame revolvers as being plus P rated. Soon after, Smith and Wesson joined the parade. I called Smith and Wesson and was told that the -1 (and any later) version of the 442/642 was, in fact, rated for plus P. Now, is that marketing hype in response to Taurus or due to changes in metallurgy and what-not, I don't know. That's what they told me. The steel versions have long been rated for plus P. No doubt wear would increase with much use. How much? I don't know. I've been toying with a 340PD figuring the scandium alloy frame is supposedly plenty strong. Pricey, though.