A little break from my history as a collector. I have received some questions from friends about how the Burnside carbine works. That being he case, I've taken some photos of my carbine as well as some of a Burnside round that I picked up at a Civil War relic show this past February. Sorry that the pictures are a bit out of order.
This is a picture of the Burnside lock with the hammer at half cocked and primed. It is primed with a copper percussion cap. Assuming that the trooper was ready to fire, at this stage he would simply have to pull the hammer to full cock, aim and squeeze the trigger.
This photograph depicts the Burnside breach mechanism lowered with the hammer at half cock. Also depicted is a Burnside round. The round is unique in its tapered design. Notice the screw on the side of the receiver and the slanted groover on the breach block. These were improvements added later in production to ensure quicker loading. The guide screw ensures that the breach returns to its rightful place in the receiver -- no muss or fuss.
This picture depicts and overhead view of the Burnside carbine with the hammer at half cock and the breach mechanism open. the trooper would insert the round into the breach. A small tube in the rear of the breach fits into the an open in the bottom of the round. The tube at the base of the breach is connected to the nipple.
Top view of the Burnside with the hammer at half cock and the breach mechanism closed. This view shows the nipple.
As I understand, the first model Burnside did not operate with a percussion cap. Rather, it used the Maynard tape system which had the excellerent to fire the weapon on a roll of thin paper tape -- hence the name. The first model also had a side lever which operated the breach instead of the lever inside the trigger guard. Only a few hundred first models were produced and I've not been able to locate a picture of one.
Hope this answers all the questions that you may, or ever will, have about how a Burnside carbine operates.