Meprolight front sights on Glocks (and Glock brand night sights) seem to be a hair wider than the Trijicons or others on the market. Don't know what they make for S&W. The down side of a wider front sight filling up the rear notch is that your sight picture may be a tad off sometimes when you can't see the light on each side of the front post. Me - I've come to prefer something bit more narrow with serrations on the ramp. Not sure if I answered very well, but XS makes their big dot sights in standard and big dot variety. The big dot may be a little too big for a factory notch. I tried the big dot once with the XS shallow V rear and found it not to my taste.