A .38 S&W Special +P revolver is all one needs for protection. For a CCW, a S&W 642 is 'made to order'. For belt holster carry or bedside, a S&W 10 is ideal. Sure, the same cylinder blank may have gone to a .357 Magnum, like a 13, 19, 65, or 66, as it would a .38 Special, but the former was heat treated differently as well as having a deeper reamed chamber. Less time in the factory means the .38s are less expensive.
I have a 2" 10, actually a -11 made 1/03, as one bedside gun, another being a SS 10, a 4" 64-8 (See below.). This is a 'current' production 64 - SKU #162506 & MSRP $758 - while the least expensive medium framed .357 Magnum now is the 4" 620 - SKU #164401 & MSRP $893. Yes, if a .38 Special is all you need, why spend more for a .357 Magnum?
Interesting tidbit. S&W's first SS production revolver was the infamous 60 - in .38 Special! Bill Ruger's first SP-101 was in .38 Special. A few of those were reamed for .357 Magnums - but limited to 125gr and below due to the short cylinder. Subsequent productions, ie, modern SP-101s, had the frame opening lengthened - indicated by an 'XL' suffix on their model number - and will chamber .357 Magnums, while permitting even their new .327 Magnum's chambering, too.
One odd piece of information. The 4" 10 and 64 have an odd history - they are super simple - and fantastic - plinkers! Whether you buy some cheap reloads or boxed commercial plinkers, you quickly find how much fun shooting can be again. Windage will be spot on - unless you 'pull' the trigger to the side. Elevation can be quickly 'learned' for different ammos and distances. It brings fun back to shooting. Oddly, my first year of ownership of my 4" 64 found it sporting some wood grips from a 66 I have - and getting lots of range time. Now, it is as shown above - loaded with Remington R38S12 158gr LHPSWCs with another six in an HKS #10 Speedloader - and secreted away for HD.
Of course, the question of why one buys a .357 Magnum when all they need is a .38 also arises. The most common answer concerns the round count, seven and eight shooters only being made in .357 Magnum . Also, the barrel length - current .38s stop at 4". My answer for the 'crud' buildup in a .357 Magnum is as has been mentioned - I have never loaded a 'real' .357 Magnum - just .38 Special wannabe's in .357 Magnum cases. So, my .357 Magnums are all plinkers - and my .38 Specials are all for protection. Gee, I am an odd duck!
Stainz