huntswnm: I suggest that you print this out for future reference.
First let me say DO NOT TRY TO COCK THE GUN while the cylinder is rusted in place. If you do you will break the cylinder hand that tries to rotate the cylinder when the hammer is moved.
I agree with soaking the Dragoon in a good penetrating oil but in my opinion you will need to disassemble the gun. This is easier than you might suspect if you follow the directions below.
DISASSEMBLY
1. Remove the grips (two screws next to the hammer and one screw at the bottom of the grip) and grip rail. Leave the brass rail in the wooden grips and set it aside.
It's a good idea to replace each screw into the holes after removeing the grips because although the screws may be the same thread as the other screws in your pistol the lengths are usually different.
2. Once the rear grip rail and wooden grips are off of the gun you will see a large screw at the bottom of the trigger guard that is holding the mainspring to the trigger guard.
Loosen but do not remove this screw. Place your thumb on the rear of the mainspring up by the bottom of the hammer and push it down and to the side. It will slide out from under the hammer releasing all of its pressure. Leave the mainspring attached to the trigger guard.
3. With the mainspring no longer pushing on the hammer, remove the three screws that hold the trigger guard onto the frame. This will allow you access to the trigger spring, the trigger and the cylinder stop.
Again, replace the screws where they came from.
4. With the trigger guard out of the way look inside.
You will see a large headed screw towards the front which is holding the bent trigger & cylinder stop spring in place. This spring has two legs on it, one shorter than the other. Get a piece of paper and a pencil and sketch how the long and short legs of the spring are positioned relative to the trigger (which is offset to the right side of the frame a bit).
Using a screw driver that fits the trigger/stop spring screw remove the screw and the flat spring.
5. Again, using a screw driver that fits the two screws that are going thru the frame from the left side, remove these two screws. This will allow you to remove the trigger and the cylinder stop from the frame.
6. Remove the screw that goes thru the hammer and withdraw the hammer and its attached cylinder hand from the bottom of the frame. It will just slide out.
The reason for doing all of this is by removing all of these pieces as I've described the cylinder is now free to turn in either direction once you have loosened the cylinder with a rust remover.
With the parts removed apply a good rust penetrating oil liberally to everything from the tip of the barrel to the back of the frame.
Get as much oil into the area of the barrel wedge and behind the cylinder and the front of the cylinder as you can.
Don't hurry. You should soak the rusted parts at least a couple of days to make sure as much oil has penetrated the rusted areas as is possible before proceeding.
7. Using a plastic mallet or a small block of brass, aluminum or wood and a small hammer tap the barrel wedge out from the right side of the barrel. You don't have to remove it but if you want to you will have to remove the small screw on the left side of the barrel.
With the barrel wedge removed place a kitchen knife or butter knife on the front of the cylinder and lower the loading lever so that it is pushing on the knife.
LIGHTLY tap the loading lever to try to move the barrel forward off of the cylinder arbor (pin).
DO NOT HIT THE LOADING LEVER HARD. Doing so will shear off the screws or break the ram.
Moving it forward about 1/8" will disengage the two pins that time the barrel with the frame. If you can get the barrel forward that far you will be able to twist it a bit to help loosen it up.
The loading levers ram should be able to move the barrel far enough to allow you to get it off of the frame.
At this stage you might want to reinstall the trigger guard and the grip (without the internal parts or the hammer) to give yourself something to grip while you try to loosen the cylinder.
While you are waiting for the oil to penetrate you should go to the hardware store and buy either a 7/16" drill bit or a piece of 7/16" diameter steel or brass rod about 3 inches (or more) long.
Place this rod or the unfluted area of the drill into one of the chambers leaving enough sticking out that it can be tapped with a small hammer.
Tap it first one direction and then the other a few times. Remember, because you removed the cylinder stop and the cylinder "hand" it is free to turn in either direction.
You can also use your wood block, or your aluminum or brass against the front of the cylinder and try tapping it to the rear just a bit.
If your lucky the cylinder will rotate or move slightly. Heating the cylinder with a Heat Gun will often help.
If the cylinder does not move apply more penetrating oil and try again.
I wish there was some magic way to break it free but at this stage I don't know of any.
To reassemble your gun after you've freed the cylinder remove the trigger guard and grips and reverse the instructions above.
Make sure the cylinder hand is installed into the hammer before sliding it back up into the frame.
2nd REVOLVER
The barrel wedge is installed from the wrong side of the barrel. Remove it and the screw on the left side of the barrel and reinstall both parts from the left side of the gun.
Again, if your lucky, Dixie sells a replacement loading lever catch for the 1851 style pistols.
This catch has a .200 dovetail so if the dimension across the outside corners of the dovetail is just a little bit larger than 3/16" it should work.
It is part number MP 1802.
BARREL CATCH
The brass framed pistol if it is a .36 caliber gun is a replica of a Confederate pistol.
If you want to shoot it remember to keep the powder loads on the mild side because heavy powder loads can damage the brass frame.