1- Bedding. The #1 is a special beast. Bedding a #1 is a special task. You can't just bed it, it has to be relieved in the right spots and tight in the right spots.
2- Barrel. Until 1990, Ruger barrel quality was erratic at best. If it is a post-1990 gun, remember that Ruger likes long throats.
3- Harmonics. Ruger #1 springs, forearm hanger, heavy hammer, and trigger all combine to make it difficult to get one to shoot. Once you have it shooting well, it will be a dream. Until then, it is a nightmare.