Round butt vs. square butt

[Florida Guy]

I'm a bit new to revolvers and want to know how you can tell if a gun is round or square butt.
Must you remove the grips to tell? That's the only way that I can see, as I see guns advertised as round or square and they both look the same outside.

 

[RossMatt]

this pic should be all you need....

 

[bamabiker]

There are conversion grips that make a round butt look and feel like a square butt. I believe most S&Ws made after about 1996 are round butt.