For about the last year and half, I've been working on my own game system off and on.  The system is a universal system and I am trying to support everything from renaissance to science fiction.  Basically, I am trying to come up with a method to take information about real world firearms and generate statistics.  Maybe someone knows a site that I can look at that explains the physics which would help with this endeavor?

I am not trying for perfection just something reasonable.  The firearm system will not be an official part of the game.  If included, it will be presented as an optional rule.  I am wanting it for the equipment list and to have some consistency.

Here is are the firearm statistics that am using in my game.

Damage type:  The game uses six different types of damage.  The ones specific to firearms are crush, ballistic, and energy.  I was thinking about having hand cannons use crush which is the same type of damage that a blunt weapons cause.  Energy is for futuristic weapons.
Damage:  The number of dice to roll for the damage.  The general rule that I am using is that all firearm damage is 2dX where X is the number of sides of the dice.  Currently, I am having the caliber of the bullet/shot dictate the size of the die.  I am wondering if that might be too simplistic.
Penetration:  The armor in the game reduces damage against attacks.  The futuristic armors have high damage reduction values which negates most damage from more primitive weapons.  The penetration score of a firearm is the amount of damage reduction that gets ignored.  This stat is currently used only for futuristic weapons but I was think it can be tweaked.
Basically, to get the damage reduction for armor of the same time period as the weapon, I add the penetration of the weapon to the armor's damage reduction.  For example if the modern armor has a DR of 3 and the time period for the weapon is a penetration of 5, the armor of the same time period of the weapon will have a DR of 8.  I went this route to keep things from getting too gritty for people not wearing armor in science fiction campaigns.
Rate of fire:  Currently, this is a qualitative value.  This can be single shot, semi-automatic, and full automatic.  This stat determines what options are available for the weapon skill.  This one is pretty easy to translate.
Strength:  The minimum strength needed to effectively use the weapon.  If relevant, strength is effectively a 3d6 roll where the average person has a 10.
Range:  This is a set of five numbers which represent point blank, short, medium, long, and extreme.  I am defining the maximum for extreme as being the maximum effective range of the weapon.  Point blank is being based on the presence of rifling (futuristic weapons have a longer point blank).  For the others, I was using percentages of the maximum effective range.  I have a problem with this though.  For some handguns, the short comes out to be less than the point blank.  Rounding is part of the issue as the game is to be played on a hex map where each hex is a meter.
Others:  clip size, ammunition, etc... probably not relevant to what I want or easily determined.

You might make damage a function of caliber and muzzle velocity, where caliber determines die size and muzzle velocity determines number of dice. This can be used for non-gunpowder weapons as well; an arrow might be 1d12 and a sword 1d20, powered as they are by human muscles.

If you do that, you can model armor by having different kinds reduce the die size of damage (padding) or reduce the number of dice that "get through" (plating). Armor values should probably be different for different types of damage, too.

I would caution you against describing any firearm as doing "Crush" damage.

Guns hurt people not because of the amount of energy delivered (mass times speed), but because bullets punch holes in people. You can deliver, by far, more energy with your fist than you can with a .38 special.

Ballistic armor works because it takes that high-speed bit of metal, and spreads the energy outward along the armor, dissipating the bullet's energy. Some of the bullet's energy will still end up delivered to the soft, squishy body behind the armor, though, even if the bullet never makes it to the target's skin. Bruised ribs are pretty common.

Ballistic armor doesn't work too well against what I would term Crush damage (consider the difference between SWAT high-risk entry armor, and Riot Police armor). Now, I'm kinda having to guess what you exactly mean by "Crush, Ballistic, and Energy" damage, but I figure you'd put fists, baseball bats, and car bumpers into the Crush category? And guns into Ballistic?

I'm curious... where do knives, swords, spears, and the like go? Do you differentiate between piercing weapons and cutting weapons?

The reason I'm asking so many questions is that there is a lot of difference between the way armor is put together, depending on what kind of weapons it's designed to protect against. Consider a stereotypical European knight's armor... all that metal plate. This armor was great against swords and arrows. It wasn't too hot against maces (Crush?), though it helped some... and it was pretty useless against the first firearms.

I guess the *real* question to ask here is what you want to accomplish with so much effort put into combat simulation. Now, me, I like heavy sim combat. Seriously. But it's not for everyone, and it's certainly not for every *game*.

What are your goals with this kind of combat system?

Bil wrote:
You might make damage a function of caliber and muzzle velocity, where caliber determines die size and muzzle velocity determines number of dice. This can be used for non-gunpowder weapons as well; an arrow might be 1d12 and a sword 1d20, powered as they are by human muscles.

If you do that, you can model armor by having different kinds reduce the die size of damage (padding) or reduce the number of dice that "get through" (plating). Armor values should probably be different for different types of damage, too.

Adam wrote:
I would caution you against describing any firearm as doing "Crush" damage.

Guns hurt people not because of the amount of energy delivered (mass times speed), but because bullets punch holes in people. You can deliver, by far, more energy with your fist than you can with a .38 special.

Ballistic armor works because it takes that high-speed bit of metal, and spreads the energy outward along the armor, dissipating the bullet's energy. Some of the bullet's energy will still end up delivered to the soft, squishy body behind the armor, though, even if the bullet never makes it to the target's skin. Bruised ribs are pretty common.

Ballistic armor doesn't work too well against what I would term Crush damage (consider the difference between SWAT high-risk entry armor, and Riot Police armor). Now, I'm kinda having to guess what you exactly mean by "Crush, Ballistic, and Energy" damage, but I figure you'd put fists, baseball bats, and car bumpers into the Crush category? And guns into Ballistic?

I'm curious... where do knives, swords, spears, and the like go? Do you differentiate between piercing weapons and cutting weapons?

The reason I'm asking so many questions is that there is a lot of difference between the way armor is put together, depending on what kind of weapons it's designed to protect against. Consider a stereotypical European knight's armor... all that metal plate. This armor was great against swords and arrows. It wasn't too hot against maces (Crush?), though it helped some... and it was pretty useless against the first firearms.

I guess the *real* question to ask here is what you want to accomplish with so much effort put into combat simulation. Now, me, I like heavy sim combat. Seriously. But it's not for everyone, and it's certainly not for every *game*.

What are your goals with this kind of combat system?