I did some math today on weapon durability on New Vegas and I noticed that some weapons could fire the exact same amount of rounds from full condition till breaking.

Since that happened more than once I figured that there must have been something they had in common so that could happen, and the answer was simple: It was their HP.

So I tried to find the relation of those two and the math showed: WD = (HP * 5) - z <----

WD: means weapon durability, how many times the weapon can be fired regardless of ammo usage per shot. HP: The weapon's health points, you can find it in both the weapon's page and in Fallout: New Vegas weapons's info tables. z: a variable that is either 4 or 5, the weapon will fire 4 to 5 less rounds than it's HP*5 and that could be caused by: 1)the game's inability to reduce the weapons HP below 0.8-1, or 2) something I haven't thought yet.

So it's safe to assume the WD = (HP * 5) - 5 is always right since any weapon will fire the exact number of rounds or just one more but not any less than that.

I have been tested to only one weapon (sawed off shotgun and it's unique) that uses more than one round each time it's shot and it was proven right.

Edit: the current form of the equation is: WD=(HP*5)*(R/WF) It is 98% accurate. WD: weapon durability, how many shots can be fired. HP: weapon's health points R: Raul. It's 1 if Raul is not companion, 2 if Raul is companion, 4 if Raul is companion and has the Full Maintenance perk. WF: bullet's wear factor, it's condition penalty or bonus.

I still have to add the Built to Destroy trait.