Name This Revolver Found In A Backyard

A reader sent us an email with some photos of an old revolver that she found in her yard, and she’s itching to find out more information about it.

Here is her email;

Hello! I’m trying to find out what I can about this revolver. I don’t know where to begin. It’s an Iver Johnson Arm and Cycle works Hammerless. It has 055187, O55187 or Q55287. I found it out in my yard so it’s in rough shape.

So for all you revolver specialists, can anyone provide some insight?