I "suspect" that since the Cobra was available in 3"(plus 2,4 & 5 in.)bbl.soon after its intro in the early 50s,that it was just a matter of changing roll mark dies to make a 3" D.S. They WERE catalogued at times.I find them listed in a 1971 listing. The post 72,shrouded version,were also listed,at least in a 1985 catalog. All that said,I once had a 1927 vintage P.P.Special,with the narrower grip frame(wood stocks)with a 3"bbl. Previous owner was a small city chief in N.H.,but gun was his personal property,so no dept. marks. Even with a grip adapter & reg.velocity .38 Specials,it was a "squirmer"in the hand with those narrow grips.Traded it off to an "advanced collector" dead even for a 7 1/2" .45 Colt N.Service,in about the same 95% shape.dfaris is right on about the uncatalogued barrel lengths,especially to police depts.There is a good article on Colt snubs in an older American Rifleman,that I will try & find. Bud
The three inch snub is so much better for up close point shooting, which is the snubnose's forte. IWB holsters are the way to carry this gun and if anyone knows where a 3" DS in the post 72 configuration is I'm interested.