Not claiming to be an expert here, but I have been packing professionally for the last half century or so.
My rule of thumb (YMMV) is that if the weapon is 16 oz or less it is a viable pocket weapon. Anything heavier goes on or inside a belt.
My exception is a heavy winter outer garment, like my old uniform reefer coat where a slightly heavier weapon can be supported by a stiffer garment.
My go to pocket weapon is a 940, actually a franken940 which is a lightweight J frame with a 9mm cylinder fitted. I did this years before a well known gun scribe tried it calling it a 9mm 640. It worked very well as a BUG for my Browning HP and could be reloaded (once) by thumbing rounds from a BHP mag into the wheelgun. I have a steel 940 that also serves as well.
If you work in uniform, a really good investment is to replace the trouser pocket where you pack your BUG with leather cut to fit the gun. Not too pricey if you cut it yourself and just have a tailor put it in. Again, YMMV....