Is the GTA Double Action revolver still obtainable?

[EjectedCasings]

I recently bought GTA and was wondering if it was still possible to get the Double action revolver, (you know, the one that gave you exclusive stuff in Red Dead story mode), or whether it was a limited time item and can't be attained anymore. Would also appreciate someone telling me some details on how I obtain it. 

 

-Cheers!

[Kean_1]

Closing per OPs request.