J frames have come with the Hogue Mono-grip and the Uncle Mikes Boot Grip as factory standard. Which do you have? The Uncle Mikes are thinner than my Eagle or Ahrends boot grips and are as thin as I would want to go.
CTC Crimson Trace made/make four different Lasergrips for the Smith J-Frame, and the third one is the best. It is exremely narrow, in width, although it looks large in profile, and has hard plastic where it needs to slide and not grab the shirt but a rubber-and-air cushion overmolded at the web of the hand ande on the front of the grip-strap for recoil control. Even with the laser at the right side, which is alot less bulge than the cylinder, it is still very narrow all over. The backstrap and butt are flush with the gripframe, except at the top for the web cushion I mentioned.
Indoors, and outside in anything but full sunlight, it makes the snub revolver into a very accurate gun, and very useful in not having to get into the typical stance, arms out etc. but aimed from the hip, held closer in.
