If you pass on any of the old "Six" revolvers, you're making a dreadful mistake. As early as 1971, NRA technical editor M.D. Waite reviewed the Security-Six. He wrote: "To the gun wise observer, the most significant physical characteristic of the new Ruger Security-Six revolver is it's lean businesslike appearance. It does not appear to have an ounce of excesss weight in it's makeup." And yet it was made specifically to handle hot magnum rounds. Today, that gun's replacement, the GP-100 had just the opposite philosophy. Not only does it have an ounce of excess weight, it's got quite a few ounces of excess weight!
In the 80s or early 90s, famed gun writer Skeeter Skelton wrote that he knew of three Security-Six revolvers, each of which has in excess of 30,000 full throttle rounds. Each, he wrote, we're still functioning fine. One was just slightly out of time but was still fully operational. That many rounds would decimate a S&W 19/66. (And I'm a big fan of the 66!)
I'm not worried about my Security-Sixes wearing out parts. When the U.S. blocked sales to South Africa years ago, the South Africans, many of them, went out and bought Rugers. The reason is, they wanted guns that wouldn't
need parts.
So don't worry about parts or the fact that Ruger discontinued them. They're strong as Gibraltar and easy to carry. The GP-100s are great if you have a boat and need an anchor our if you're saving up to make a manhole cover. Ruger stuck a mainspring strut onto the GPs and added way too much weight to the barrel. Thus the balance of the gun was horribly altered and the new guns can't touch the older ones for quality and innovation. Of course, more people carried their guns back then. Hiking, camping, hunting -- the S&W 66s and the Security- and Speed-Sixes were the guns to take.
Now the present Rugers are the guns to lug!