I was told that when S&W started using the lighter weight titanium cylinders in their first .38 Spl Ti J-frames, they discovered that the guns were suddenly just enough lighter than their steel-cylindered, aluminum-framed models that they could sometimes encounter lead bullets jumping the crimp. The potential was there, so they specified jacketed ammunition in the Airlites, and then also in the Airlite Sc guns (having the same titanium cylinders).
That's why I wanted the Airweight with the steel cylinder, so I could still use lead bullets ... and I simply preferred the stainless cylinder/barrel.
Now, it seems the newest generation of the Sc J-frames may be approaching the point where technology and 'human' engineering (strength & skills) may not always combine to bring about the optimal, desired result for some folks ...
For instance, I was told by someone at the factory that they'd learned of a complaint from the owner of one of their .357 Magnum rated Airlite J-frames involving jacketed bullets jumping the crimp and binding the cylinder, apparently with 158gr jacketed .357 Magnum ammunition. The gun was checked and found to be in proper working order and without problems. Since S&W takes customer complaints seriously, they did some further testing.
They discovered that if the Sc J-frame wasn't held in a properly strong & firm grip that it might sometimes be possible for some of the harder recoiling, heavy-bullet Magnum loads to generate enough recoil to result in bullet jump, even with jacketed ammunition. The combination of the lightweight gun moving rearward under recoil ... not properly supported by a strong, stable grip ... combined with the weight of a heavy bullet, even jacketed ... and inertia ... apparently
might still result in bullet jump. Depends on the shooter.
In other words, it might be possible for someone to 'limp-wrist' one of the Sc Magnum J-frames with the wrong combination of grip strength/technique and heavy bullet Magnum ammunition. Apparently, according to the fellow I was discussing this with, this sort of thing hadn't been encountered during R&D, seemingly because the test shooting hadn't considered limp-wristing. These little powerhouses require a properly applied, strong grip.
Maybe it's a case of being welcomed to the world of some folks 'being able' to limp-wrist (and/or improperly grip) some polymer-framed pistols and experience functioning issues. Then there are the other folks who just don't understand how it's possible to limp-wrist a polymer-frame pistol and cause a malfunction, because they've never experienced it. Maybe their skill sets, techniques and physical abilities just didn't combine to create the potential where they could experience it ... not without a lot of deliberate effort, anyway.
Personally, whenever I've shot Magnum ammunition from a couple of Sc J-frames I was
really hanging on, and couldn't imagine using a looser, more relaxed grip or unlocked wrist.
We've all probably encountered folks who seemingly didn't easily understand what a firmly locked wrist really was, or why their grip couldn't start relaxing the moment they 'finished pulling' the trigger. Some folks may be gifted with superior hand & eye coordination and reaction time at birth, but learned skills & techniques are still learned ...
Bottom line? I don't have the answers to these sorts of questions.
All I know is that when I've repeatedly asked different folks at S&W if I could use 158gr LHP +P ammunition in my 642-1, I was told that it was rated for use with +P ammunition, and that lead bullets were considered appropriate for that model.
Something I keep in mind, however, is that S&W, like other firearms manufacturers, doesn't have any direct control over the ammunition produced by ammunition manufacturers, or what's selected and used by the customers who buy and shoot their handguns. I prefer to use only new, high quality ammunition produced by one of the major manufacturers, which suits whatever recommendations/restrictions are made by S&W, and I try to give each round at least a cursory visual & tactile inspection before I load it in my guns.
I dislike cleaning lead out of the cylinder charge holes, though, and try to limit my practice and qualification to jacketed ammunition as much as possible.
Now, if only S&W would decide to make a 642 with a Scandium frame, still using a stainless steel cylinder.
Or even a 442 with a Scandium frame and a carbon steel cylinder, and I'd try to be a bit less lazy.
If I ever decide to buy a Magnum-rated J-frame my current thoughts are that it would be a steel-framed model, for the extra weight, and the hopeful controllability advantage it might offer
me. If nothing else, at least it might not feel like I was trying to stop a boulder, the size of VW, as it rolled by me by swatting it with an aluminum baseball bat.
