First, a warning. Those revolvers are very complex and parts, especially springs, are easily broken or lost, and parts are hard to get and expensive. Most gunsmiths won't touch them for that reason.
You can remove the sideplate, but be sure to take the tension off the mainspring first. And when re-installing, watch not to hurt the hand spring, which is also a bear to replace. Note the way the stud in the inside of the sideplate works to keep the hand spring in place when installing the sideplate.
If you are lucky, the problem will be dirt or crud, but the bolt spring is very fragile and they often break. Gun Parts had some, but I think now they only have the whole bolt assembly at $25 or so. Also, many replacement bolt springs are also broken. The back end has a little curve where the spring bears on the rebound lever; that part is often broken off and the spring doesn't work right. Bolt springs can be made (and I have made them) but it takes a lot of patience and a knowledge of how they work.
The gun can be safely fired with the bolt inoperative. As I noted earlier, the first models did not have the bolt, leading to the possibility that a soldier would fire a couple of shots, then holster the gun. If the cylinder turned while the gun was being holstered or drawn, the next round up might be a fired cartridge, not a good situation in combat.