WARNING: inexperienced and moderately experienced shooters often assume, when they don't hit the target, that it is because of their sights. Especially when they shoot a group, but it is off center, say to the low left of center, they assume that the group means they are shooting right and the sights are off. Usually it is because of their hands and changing and adjusting sights won't really help - it will just hide the problem, as long as you always shoot from the same distance.
The person who has nothing for which he is willing to fight, nothing … more important than his own personal safety, is a miserable creature [with] no chance of being free unless made and kept so by the exertions of better men …. John Stuart Mill