Naw you won't need a jacket to OWB carry a 4" K-frame. You just need a good high ride holster. I still carry my 4" Model 58 in an old Roy Baker Pancake holster like I did back in 1978. It still conceals just as easy.
People are constantly amazed that I'm carrying a 4" N-frame.
Quite often I just wear an oversized T-shirt.
The Galco Shilouette works great too if you don't mind the muzzle/front sight being exposed. The Galco FLETCH also works well.
So does the Bianchi pancake.
And I have an old Safariland paddle that conceals just as easy too but I don't know if they still make it.
And the DeSantis high ride tumb break has also become my personal favorite for my 3" Model 29-3.
If I was starting over again I'd contact
A.E. Nelson down in Oregon. They make some exceptional products and they still cater to us revolver guys.
There are only three secrets to carrying a 4" revolver
Carry it high enough to conceal but not too high to hamper your draw.
Choose Grips that don't snag, drag or protrude.
But the real secret is to select a holster (and belt) that pulls the gun and grip tight against your body.
