That depends on what you mean by reliable. It is common to be able to get dates that roughly match the evolutionary timescale. The published literature mostly reports dates which match that timescale. However, it is also common to get dates that do not match the evolutionary timescale. The exact proportion of "accurate" to "inaccurate" dates is difficult to ascertain from the literature.
Two factors are involved. First, in a given rock, for example lava, at least 4 dates can be obtained: the whole rock, and three fractions (light density, heavy density magnetic, and heavy density nonmagnetic). These can give dates with the oldest being over 4 times the youngest, on the same rock. The choice of which rock fraction's date to accept is not clearly based on objective criteria (other than the evolutionary timescale itself)
Second, some dates are not reported, because their results are not "acceptable" . One published study mentioned that approximately 85% of the data from one source was not published. The choice of which samples to publish is also not clearly based on objective criteria.
2010 Arthur V. Chadwick, Ph.D.