The Heavy Holy Grail of Colt Revolvers- The rare Colt Walker Model 1847 is a 6-shot, single-action revolver weighing in at 4-1/2 lb measuring a 1-1/2' in length. It was the weighty brainchild of Samuel Colt Samuel Walker. Walker met with Colt in the 1840s to propose improvements to the Colt Paterson revolver...the result was the Colt Walker. Fewer than 10% of the 1,100 are known to exist today. Due to their rarity, these guns are the Holy Grail of Colt revolver collecting. NRA Museums.