4" barrel, it has to be my 1972 vintage Model 66 but I have a very early first year 9 1/2" barrel scoped Ruger Super Redhawk that will put 5 rounds in one hole at 25 yards.
4" Colt Diamondback
4" Ruger in 327 Federal
I have 2 4" Model 67's just can't get them to shoot with that Diamondback.
My most accurate Smith is my old Model 25-2.- gene