I wouldn't try to take out the drum or breechplug.
See the diagram and the thread for reasons why.
http://www.thehighroad.org/showthread.php?t=329660
There's many ways to check to see if the barrel is loaded or not.
First of all, the bottom of the powder chamber is usually at the same point as the clean out screw which is next to the nipple that's threaded into the drum. That point could be as much as 1/2 inch from where the loaded ball would be rammed home in the breech if it were loaded. Then a round ball would occupy another 1/2 inch of barrel space from there. So that's about where the ramrod would be measured from in an empty barrel, the beginning of the powder chamber which can be viewed in the cutaway picture.
I would remove the cleanout screw and nipple to see if there was powder in the drum. If powder wasn't visible, then I would insert a thin .22 rifle brass or aluminum cleaning rod into the muzzle to see if it will reach all of the way to the bottom of the barrel and become visible at the cleanout screw. Some flash channel designs may not allow it to become visible, so then alternatively I would try to probe the shape of the bottom of the barrel to see if the powder chamber shape is identifiable verses the shape of a projectile. One is a hump and the other is a dip, and could further be a narrow dip. A brass breech scraper can also help to tell if your probe is at the bottom of the barrel or not.
Some of the new powerful LED flashlights can be used to peer into the barrel from the muzzle end to light up the inside of the barrel all of the way to the breech. See if any light is visible through the clean out screw opening. Go into the closet if necessary to see if there's any faint light coming through.
If progress is still not made then while shining a light into the clean out screw opening in the drum, I would peer into the muzzle to see if any light could be detected coming in from the other end. I'll sometimes lift the back end of the barrel up near a light bulb and turn it until the light finds a path in so that I can detect it. Or I'll have someone hold a strong light at the clean out hole to allow light to enter the back end of the barrel. I do this after cleaning an empty barrel to see how clean it is.
If the bore is shiney enough, the light coming in through the back of the barrel should be reflected and be visible to the naked eye at the muzzle. It will light up the barrel's shiney interior even if only faintly. Wearing safety glasses to keep crud out of one's eye is a good idea if the barrel is being lifted up and tilted towards it. Sometimes it helps to place a hand around the muzzle and to fist it, and then to place the eye against the fisted hand to peer in to eliminate other sources of light and to allow the naked eye to pick up the faint light in a dirty barrel. If light can't be detected, the bore can be swabbed to make it shiney enough to reflect some of the light.
But if the light is blocked and the other methods aren't working either, then a decision needs to be made about what kind of obstruction there could be in the breech.
That's why careful probing and measuring can all help to more accurately deduce the situation.
I think that the 1 in 48" Bobcat prefers round balls, but it might shoot some saboted bullets and bare lead conicals equally well.