The Colt Cowboy is a near-SAA-clone - it has an internal safety like a Ruger. Quality is known to be VERY bad, among the worst.
The Beretta Stampede is the first results seen of the Beretta buyout of Uberti. They've re-thought the Colt Cowboy concept and grafted a transfer bar safety onto the SAA yet again. Early reviews are actually quite good, they may have gotten it right.
Of the non-safety true clones of the SAA, the USAF Rodeo has the best rep in the sub-$600 price range. If I was shopping for a non-safety SA, that'd be my first choice by a mile.
The Rugers are bigger, WAY tougher and have a safety.
There are ways of modifying a Ruger so that the ergonomics are closer to the SAA in terms of hammer and trigger reach. The way you can get there pretty cheap is to start with the 45LC Bird's-Head in the 3 & 3/4" barrel, and swap hammers down to the SuperBlackhawk or Bisley types to get the hammer reach down to what you want. The bird's-head grip, especially with thinned factory panels or the Eagle Gunfighter skinnier panels, may not look like an SAA grip but the basic ergos are pleasantly close. The shorter barrel gets speed up the handling and overcome the heavier frame and cylinder of the Ruger over the real SAA-patterns while being long enough to give decent ballistics. You'll want two other cheapo mods: a Belt Mountain base pin to tighten the action and provide a set-screw ($22, send the cylinder off for final throating to a couple of good machinists doing these up right (less than $50) and perhaps a spring kit ($17).
There's a TON of aftermarket support for Ruger SAs...much like the 1911s and AR patterns. You can spend a lot more money as desired, the recipe above is the cheapest way I know of to produce a functional SAA-clone out of a Ruger.
See also this thread for upgrade bits:
http://www.thefiringline.com/forums/showthread.php?s=&threadid=80872
Oh ya, one other detail: Georgia Arms has apparantly just came out with a really nice 45LC load for defense or light hunting, involving a 200grain Gold Dot JHP moving at almost 1,100fps. $17 for 50, and that's new vs. reloaded. Not at all bad. That load should be safe in all of the full-frame modern SAA clones, the Taurus/S&W DAs and of course the Rugers. Avoid in open-tops, breaktops and cap'n'ball conversion cylinders.
It's not on their site yet, but several people have commented on these. They're the ultimate for CCW, in my opinion...ballistics are the same as the Cor-Bon 200 but the projectile is worlds ahead. I want to see Cor-Bon respond by loading the 165 Pow'R'Ball in LC cases
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