My father-in-law shot IMHSA for years with a variety of pistols including now mine (his first). S&W model 29 with a 61/2bbl, factory white outline and front red ramp. 40 yeasts ago I shot it regularly out to 200. I don't just my eyes past 100 with the short focal length. He moved quickly to a Ruger Redhawk .44 mag 71/2bbl to handle the beaver loads better. Then moved to T/C single shots and finally to Remington XP 100. The T/C and XP 100 all wear IMHSA specific sights and are excellent. I would check there for information but you may not want the possible gun mods.