First of all, I would like to assure you that I have done my homework when it comes to understanding damage calculation in Monster Hunter. My question is somewhat advanced because understanding damage calculation is a prerequisite.
Total Damage Output = ([Physical Damage Output] + [Elemental Damage Output]) * Overall Defense
And of course it gets more complicated than that.
My question is on the calculation of the Elemental Damage Output
for, say, a Light Bowgun. Most weapons in the game have a stat called Element
, which shows the Elemental attack
of the weapon. This value is used in the computation of the Elemental Damage Output
as follows:
Elemental Damage Output = (Elemental attack / 10) * Elemental effectiveness
The problem with bowguns is that they do not have any Element
stat. So as I looked into the question (I told you I did my homework ^^), I found out that the Element
stat for bowguns was contained within elemental shots (e.g. Flaming S, Water S, …). For example, according to this beautifully written tutorial on bowguns that I urge every aspiring gunners to read, the stats on Flaming S
is 7 + 45 Fire
and I would like to know what it means:

I think the
7
is the motion value used to calculate thePhysical damage output
so that it will be 7% of the weapon'seffective power
(which takes into account theraw damage
, theweapon factor
and theaffinity
. Please, correct me if I'm wrong. 
I don't know what to think about the
45 Fire
damage. If such a small value is used as theElemental attack
in theElemental Damage Output
calculation (in the formula above), it makes no sense because bowguns would be severely disadvantaged because the actual elemental damage dealt would be 4.5 times some elemental effectiveness, which is usually a low percentage. So, this interpretation is likely not correct. Or am I to see the45 Fire
damage as the result of450 / 10
, which then needs to be multiplied by theElemental effectiveness
?
Your help is greatly appreciated.
Best Answer
As you correctly state the 45 of elemental damage stands for the 450/10 this is why bowguns are masters of elemental damage.
About the 7 in the formula is the physical damage but it is the total damage it will add that is already precalculated from a previous example
so the final damage would be 7/physical defense and 45/monster elemental defense
source : http://gaijinhunter.tumblr.com/post/73946102476/mh4howdamagecalculationworkssimplified