Hi Kevkuck, and welcome to Coltforum.com.

Our very own member, Brent (bjt72 is his name here) is the Manager of the Colt Custom Shop, and is really great at fixing any problems a Colt might have. Why don't you send him a PM (Private Message) here, and I am sure he will help you find the correct solution to your Colt's problem.

Colt experts will come here shortly and offer good advice.

 

Sounds like the side plate and not a crack.

Picture?

 

Are you sure it is not the outline of the side plate you are seeing?

 

The MkIII Series guns are really tank tough. I would bet it is not cracked. However, it is my understandiong that Colt still works on the MkIII Series guns. If it is cracked maybe they can help. Good luck.

 

Welcome to the Forum. What you are seeing is the joint between the frame and side plate. Your frame is NOT cracked. Notice there are two more "cracks" in the area below the cylinder and towards the bottom rear of the left side. Those are also joints between the frame and the side plate.

You do not need to do anything, least of all contact Colt. Just enjoy your very strong Colt revolver and shoot it as much as you can.