If you could only do one; weigh or size which would you recommend? Or if you chose to do both, which would you do first?
Same opinion... Accuracy/consistency due to head size is much more unpredictable vs pellet weight. Of course it depends on the rifle...some are more tolerant to head sizes vs. others. Pellet weigh (if measured) will always have a predictable/calculable outcome as far as accuracy. At a certain distance weight may become more important (i.e. at 80-100 yards) than head size assuming the head size used at shorter ranges (i.e. at 50 yards) was already ok in that rifle. But if head size does not match with the rifle from the get go...you may not even get decent accuracy at 25 yards."REAPER0D"I think its been proven that if a pellet doesnt fit properly it affects the accuracy more often then pellet weight. some have even gone as far as creating a pellet resizer to be EXACT with every pellet and shrink the head size down, and some have created rigs to widen out the head size.
i think head size is more important personally then weight.