As lite as the 642 is how much weight could you shed? Ti barrel and cylinder, maybe even the center pin and ejector. Where else could you drop weight? DRI always found it interesting how different people interpret recoil… not implying anything rock185, but what one person notices, another doesn’t. Different strokes, right?
I’ve had my 642-1 since 2009. In 2015, I converted it over to 9mm via a Pinnacle converted cylinder. Still have the original cylinder, so I have sort of a convertible, but I haven’t shot .38s out of it in years.
Never found 9mm, specifically 147 grain Hornady XTP, to be any worse than .38 +P (used to carry 110 grain Hornady CD). I do practice with 115 grain UMC bulk, which has a similar POI as my carry load (and it’s cheap to shoot). Gun didn’t blow up, burst into flames, or harmed me in anyway since it was converted. Other than the conversion, had the gun and both cylinders done in NP3 Plus, run LG-405s, and a LaserMax weapon light (make sure to say that because I always get questions on why I have two lasers when I post pictures).
If I had to do it all over again… I’d probably see about doing a converted Titanium cylinder. Would cut the weight down by about what a load is, so I’d be carrying a gun loaded that weighs like my current setup, unloaded. That revolver goes everywhere with me (off duty) at its current weight, because it is so easy to carry.