While I'm at it, some of the modern sidelock guns like those from TC have a "half cock" position that leaves the hammer too close to the nipple to allow you to cap it. It is necessary on these guns to bring the hammer to full cock to get the cap on.
That's fine if you want to shoot the gun right away but, if you want to put the gun in the half-cock position without shooting it there is a right way and a wrong way of doing this.
Lets say you've loaded the powder and patched ball or bullet with the hammer at half cock and no cap on the nipple on a TC Hawken. Now, you want to cap the nipple so you pull the hammer to full cock and install the cap.
Because these guns have double set triggers on them, they also have a "fly" in the lock. The fly's job is to prevent the locks sear (the thing that holds the tumbler and hammer in position) from entering the half cock notch when the hammer is falling from a full cocked position. Due to this, if you try lowering the hammer while using your thumb to control the fall, the gun will not go directly into the half cock notch. It will keep on falling until it rests on the capped nipple if left to its own devices.
The only way to get the hammer to a half cock position is to slowly lower it down until it just about contacts the cap and then, pull it back up slightly until you hear the "click" of the sear falling into the half cock notch.
I mention all of this because of one of the "tricks" a fly can pull on you that leaves the gun is a totally unsafe condition.
Like I said earlier, the fly's job is to prevent the sear from entering the half cock notch while the hammer is falling and in order to do this, it stands proud of the tumbler. In this position sometimes if your lowering the hammer from the full cock position to try to get it into a safe half cock position the sear will "hang up" on the fly and the hammer will stop falling.
When this happens, the gun will appear to be at half cock but because the fly is the only thing that is keeping the hammer from falling, the slightest jar of the gun can get the fly to release the hammer. Just sitting the gun down against a hard surface like placing the gun into a gun rack can be enough to make the hammer fall and the gun to fire.
This is the reason I always lower the hammer slowly until it rests on the capped nipple and then slowly raise it until I hear the "click" of the sear entering the half cock notch before I consider the gun safe to sit aside.
By the way, a fly is in almost every lock that is designed to be used with set triggers so this "fly hang up problem" exists with all guns with set triggers, not just the TC, Lyman and other factory guns.
