I have weighed several heads and there are only a few that actually weigh what they are suppose to.
Muzzies are almost always different than stated and also inconsistant.
Most all mechanicals are off and inconsistant.
THe most consistant field tips I have found are Gold Tips. Every one I have weighed all weigh as advertised.
Slick Tricks all seemed to be dead nuts on though.
I too have found this to be true. Every single ST I have put on the scale all weighed 125 grains on the nose.