If you want the best inherent accuracy, skip any Colt design. The rear sights are on the hammer and the barrels are pinned on.
Technically valid, but a few weeks ago, using a Traditions Pietta '51 Navy .44-- from a blister pack with starter's kit ($200.00 total a couple years ago):
25 yards, six consecutive shots in 2 & 5/8", standing, unsupported, two-hand hold. 28 grains Goex FFF, .454" ball and lots of Bore Butter.
Granted, I had replaced the front sight with a taller one, and then Dremeled the hammer notch to get the windage right, but that had nothing to do with accuracy-- just POI. It's otherwise stock and has fired hundreds of rounds. All rounds hit in the upper portion of the black with a bulls-eye hold on the NRA 25 yd. slow-fire pistol target #B16.
With all the use it's gotten, I'm sure the barrel wedge has fit itself nicely to the barrel and arbor, and that the barrel bore is lapped in from regular wear.
Just got a Pietta '58 on sale at Cabelas. A bit rough in places compared to a 600-dollar Smith, but it's a lot like the '51 was when new. It locks up very tight and in line with the bore. The cylinder gap is almost too small (the '51 has a
lot of gap). The crown has noticeable, but very minor burring inside-- stuff like that. The finish on the top strap shows definite signs of repair at the factory. In some minor sense I consider these project guns.