I carried a snub nose revolver M60 for 41 years and always disliked the bulk of a speed loader for CCW. Instead, I bought a leather pouch with three pockets that held two rounds each. I practiced with it until I got good enough to actually reload "by hand" just as fast as I could with a speed loader. I reloaded two rounds at a time (2-2-1) and you'd be surprised at just how efficient you can become by practicing. The pouch was very flat and was so much easier to carry.
BTW, it is much faster and easier if you just want to replace a few spent shells on the fly instead of a full reload. I never liked using or carrying speed-loaders.