I'm looking at new 4" revolvers.

Which would you choose?

Oops. You said "revolver". Change my vote from Kimber to Colt. (Kinda like how the dems changed those Trump votes to Biden.)

It is hard to say about those two,given the newish guns they offer. I have heard Kimber makes quite a revolver now and seem very nice, at least from those I have held. Colt is an iconic name and their older/original revolvers are quite nice but expensive. I have have heard from some local shooters about some issues with the newer 357 pistols although I don't have any experience myself with them. Any reason in particular to own one from these manufacturers? I am sure you will hear from people hear about how wonderful S&W revolvers are,myself included and there is a reason for that. S&W makes a great gun right out of the box and have a great track record with quality and performance. I am not knocking Colt or Kimber and I thought about getting one those myself a little while back but with the way things are heading,politically wise, parts availability/reliability/serviceability would be my main concerns.

Use?  Which model Colt?  

I've looked at Kimbers but never shot one and don't know anyone who owns one.  They seem quite nice.

For the record, I have a 3" K6S.

For a 4" target gun, it really depends on which model Colt.  Python > King Cobra Target.  But I've heard that the grips on both could be improved for a range piece.  The King Cobra Target is a closer direct comparison to the Kimber K6S, but the Python would be considerably better in every metric of performance.

I thoroughly enjoy my 3" Kimber K6S DAO, but finding larger, more hand-filling grips can be problematic.  The Comfort Core grips are okay, and the Hogue Bantams feel a little better, but there is no huge squishy grip for the Kimber frame like there is for the Colts.  The DAO mechanism is smooth and crisp, which makes me wonder about the DASA models, but the hammer would poke me IWB.

Another nice option, IMO, would be a Ruger Match Champion.  Great sights, robust mechanism, and with the polished improvements given to that model I consider it to be on par with my S&W L-frame, but stronger.  I would still guess the Python to be superior, if you could find one.

Im not going to vote. I like them both

As for the why, I don't own a revolver and I've always wanted one.

It'll be a range gun mostly.  I don't plan to carry it.

Keep the responses coming.  Thanks.

Adjustable sights? Fixed sights? Does caliber matter?

I personally would go with a older S&W revolver. Model 10 or 64 in .38, Model 19 or 66 in .357

686 or GP100

The ones you listed are more suited for carry. If you want to shoot magnums they wont be very comfortable.

Look into either K or L frames or a gp100.

If it is a range toy, neither.
I agree that a Match Champion or a 686 are much better range and woods choices.

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The K6S is a great gun I have one but the New Colt python beats it. I just bought one. Now for the newer Colts that are not the python the Kinber wins hands down.