I've only purchased two NIB S&Ws, a 686 and a 642. Both came with stiff, gritty DA triggers out of the box. The 642, with a few thousand trigger cycles (dry and live) and an internal clean/relube, had a very noticeable improvement in action quality. Nice and smooth with a clean break. The 686, OTH, is going to need an action job. Though the DA is useable, it leaves a lot to be desired. One of the cruddier pulls of all my revolvers. Stiff, with lots of roughness in the last 1/8" before release.
22 rimfires are particularly sensitive to mainspring tension. My Model 17 (made in '59, bought used in '06) was having a number of light strikes. I figured the mainspring may have had a lot of cycles on it, given it's age, so I replaced the mainspring with an OEM part from Numrich. Now I only experience about 1 light strike per 200 rounds. I can live with that.
You should not dry fire you Model 17, unless you have snap caps or spent cartridge cases. But after pulling the trigger a thousand times or so, you or a gunsmith could clean out the internals and relube. Hopefully, this will take care of the problems you are having with the stiff trigger pull.