What factor reduces the accuracy of radiocarbon dating

At its most basic level, carbon dating is the method of determining the age of organic material by measuring the levels of carbon found in it.All living things absorb both types of carbon; but once it dies, it will stop absorbing.The C-12 is a very stable element and will not change form after being absorbed; however, C-14 is highly unstable and in fact will immediately begin changing after absorption.Reducing the sample size doesn't reduce systematic errors and it doesn't make any sense to improve statistical errors past the point of no-return in any experiment. contamination, increasing the count of atoms won't help, either.There is, of course, also the component of cost and experimental complexity.Lawrence during WWII used calutrons to separate Uranium 238 and 235, but it was really expensive and inefficient.To back up @Curious One - the detection limits are pretty darn small (Purdue's lab lists detecting one part in 3E14 of C14 vs C12).My understanding of the limitation of radiometric dating is that background radiation swamps the radiation from C14 once the remaining atoms get few enough in number.Accelerator mass spectrometry seems to actually count every atom in the sample, meaning background radiation doesn't matter.In last Tuesday’s lecture, radiocarbon dating was covered briefly.It is an essential technology that is heavily involved in archaeology and should be explored in greater depth.