Royal Barnes said -
" Pietta and Uberti make good Colt clones........... and there's no such thing as a 4th Gen.Colt' s SAA just 1st ,2nd and 3rd."
+1 Uberti (Cimarron or Taylors). Unless you really are budget limited, skip the base Uberti (flat finish, some w/ brass gripfrmes) popular in the big box sporting stores, and go with the polished blue and case hardened models. you won't regret. Love my Cimrron P (as well as the old/original and New Vaqueros). Piettas are said to be great, but they too have "gone commercial" with lesser finished base models - so beware.
True enough on the "4th Genertion" - there is no formal designation (we've ll heard "just a cylinder bushing doesn't signify enough of a design change to warrant a new generation," which is Colt's stance, but good enough for me is that my Coltsmith of twenty years, one of very top Colt experts and tuners in the country, uses it as "most everyone" knows he's then talking about late (post 2003) 3rd with the removeable cylinder bushing (as well as what many believe to be better overall quality pieces, which my 2008 can attest to, A-B'ing with a friend's mix of earlier 3rds)--without having to go through all that explanation. Yes, "late 3rd" also works, but then almost always prompts the question "How late?" Or "Does it have the removeable bushing?". For an old codger "recent or late" could mean late 80's-on. He does know well enough with a neophyte to go through the "late 3rd, bushing, etc," explanation. "4th" is a useful practical or pragmatic definition for many. "4th (late 3rd)" works also for clarification for mixed audiences.