The colt walker came out before the colt Dragoon???
What are the differences between these two guns?
why did so many of them blow up ?
Yes, The Walker Colt came out in 1847. It was the second revolver Colt made. The first was the Paterson Colt. The Paterson Colt was quite different than the later Colts. Much smaller, with some major differences in the appearance.
Basically, Colt went bankrupt after the Paterson Colt. He spent about 10 years doing several other things, but in 1847 he was approached by Captain Walker of the Texas Rangers. Walker wanted a very powerful revolver for his Rangers and he and Colt worked out the design for the new gun. It was huge, the cylinder chambers had a powder capacity or 60 grains of powder for each chamber. Stop and think for a moment that the later 45-70 cartridge used 70 grains of powder, and that will give you an idea of how large a powder charge the Walker could hold.
There were only a grand total of 1100 Walker Colts manufactured. 1000 went to the Texas Rangers, the rest were sold commercially.
Colt realized the Walker was just too big to be practical, so rather than make more, he went back to the drawing board and came up with the Dragoon series. Both were 44 caliber. The Walker weighed 4 1/2 pounds. Its barrel was 9 inches long. Too big and heavy to be worn in a belt holster, they were often referred to has horse pistols, carried in holsters slung from the saddle. The Dragoons were still big, heavy revolvers, but not quite as big as the Walker. The Dragoon barrel was 7 1/2" long, the cylinder chambers held about 50 grains of powder. The Dragoons used a new device to keep the loading lever snugged up under the barrel, a spring loaded latch under the muzzle. The Walker had a spring loaded latch near the loading lever pivot that did not work very well. Loading levers on the Walker often dropped down from recoil. The loading ram would enter a chamber at the bottom of the cylinder, effectively locking up thee gun until the lever was raised again. There were several different models of Dragoon produced up until 1860. They were still very heavy revolvers, they weighed about 4 pounds 4 ounces. I shot a borrowed pair once at a CAS match. Really heavy. Consider the Colt Single Action Army only weighs about 2 1/2 pounds.
They tended to blow up for two reasons. The power capacity of the cylinder was just too much and metallurgy was not as advanced as it is today. Walker cylinders were made of iron, not steel. Often the iron was poorly made, with porosity in the metal. Combine that with the huge powder charges, and it is a recipe for cylinders to blow up. Also, in the field some troopers were loading a conical bullet backwards, which may have contributed to the problem by raising pressure.
By the way, Colt continued using iron, not steel for frames and cylinders right up through the early Single Action Army production into the mid 1880s. But the powder charges were not so huge, and most of the iron cylinder SAAs survived just fine.
Walker Photos 
