I have a 642 CT and a 638. The sights are a huge disadvantage on these pistols, but they have always pointed naturally for me and carry so well. The two things I changed that improved my accuracy with +p carry loads the most:

1. Upgraded both pistols with Wilson Combat spring kits. (Watch some youtube videos before attempting the swap, it is easy enough that anyone can install the kit after seeing those). Also, make sure you have the right sized screwdrivers for the side plate screws. Brownells sells an inexpensive kit with the exact screw size bits.

2. Spent more trigger time with light Remington 148gr wadcutter loads to work on eliminating flinch/smoothing out my trigger pulls. I found that shooting +p loads was a lot easier and I wasn't anticipating recoil as much.

It has taken me a lot more practice to become proficient with the little J-frames than with my G26. They are accurate little revolvers, especially my 638.