New 27 4th Screw?

[413Maxwedge]

I'm considering getting an N Frame revolver in .357 and while looking at the new models on S&W website I noticed that the Model 20, 27(s) and "Heavy Duty" all have a 4th screw. What gives? Is this just for a vintage look?

I have 4)J's, 4)K's and 3)L's, but no N's yet.

 

[SLT223]

Yes. You can even remove and reinstall the side plate w/o removing that screw.