Dipper has the experience advantage due to having dealt with supernatural conflicts and science-fiction gadgets, whereas the Hunter is skilled at fighting more realistic creatures using realistic weapons. I'm not sure if Dipper's weapons are suppose to be standard equipment or optional equipment, and their range is considered as "higher" than Standard Melee Range, which is vague, whereas the Hunter's weapons have more clear long range listed on his profile. I feel like the Hunter would be skilled at navigating in a forest, but the characters are set as bloodlusted and Dipper has stealth skill on top of being more familiar with the location, so I imagine Dipper would be the most likely of the combatants to surprise the other.
Dipper's durability is ranked as 25.796 kilograms of TNT, whereas
the Hunter's firearms are ranked as 8.530 kilograms of TNT, so the Hunter's firearms wouldn't one-shot, and Dipper's Class 10 lifting strength would allow him to disarm the Hunter without issue if Dipper would get close enough.
My conclusion is that I think Dipper has enough of the right advantages for him to win the battle, so I vote for him winning.