Adam, yes and no. It is usually an easy job for a pro, but not easy at all for a novice. The relationship between the sear and the tumbler is critical, and usually must be stoned in order to improve the trigger pull. It sounds like either the notch is too shallow, the angles are wrong or the sharp edge(s) has worn away due to use and/or steel in that parts that are not hardened well. A good trigger man can fix you up if it needs deepening or otherwise recutting a bit. If it's soft metal it just won't last after it is recut. He will know this, however, by how easily the stones cut and can sometimes harden the parts after stoning.
What make sidelock is it?
Stan