It uses the "K" frame. The Model 66 was the Model 19 in stainless, and with a target trigger. But it was only made in .357 Magnum; it was never made in .44 Magnum. That was the Model 29.
Look on frame inside the cylinder area to find the model number of a Smith and Wesson 357 mag snub 2 in stainless barrel
The Smith and Wesson K frame revolvers were made from 1946-1983.
30
The Smith and Wesson model 19-5 was made from 1982-1987.
No such model number.
100-500 USD
100-435 USD
50-625 usd
50-600 usd
50-675 usd
50-450 usd
100-650 usd