Guns stats

[GWJ]

Hey!
I wondering if is there any public formula or spreadsheet to convert real life wapons' statistics into GURPS. There is a lot of various guns models in High-Tech series or Tactical Shooting, but part of my players are interested with guns, and they want to have >this particular weapon<, for example Panzor Jackhammer (from one of the last game sessions - luckily I found it somewhere on the forum), or various new weapons (released after the high-tech), or even something non-existing, based on self-invented "stats" it would have in the real life?

[Fred Brackin]

Requests for Gurps stats for "Kewl New Weapon X!" are increadibly common but when it turns out that Kewl New Weapon X is =just another 5.56mm assault rifle the answer turns out to be "same as the M-16 except for weight, price and possible magazine capacity. Just use the real world numbers for those.".

This will turn out to be mostly true for any gun in a caliber that gurps already has stats for.

However, if you've jsut got to ahve a formula see this site...

https://gamingballistic.com/

[Pursuivant]

If you search for "GURPS" [fill in the blank weapon]" you can find some decent fan-made resources.

This site has a number of converted GURPS 3E weapons and a few new ones.

https://wiki.rpg.net/index.php/GURPS_Weapons

Beyond that, this site has a GURPS ballistic computer that can be converted to standard GURPS rules with little problem as long as you know info like barrel length of the gun, grains of powder and lead for the bullet, and bullet shape. Convert kg to lbs. to get weapon mass and divided by 3.5 to convert damage into dice of damage:

http://panoptesv.com/RPGs/Equipment/...lackPowder.php

If you're seriously into DIY GURPS guns, have your gun-bunny players give you decent info on the weapons they want to see in the game. Necessary stats are: weapon mass, weapon length, actual gun caliber, number of shots, barrel length (at least for long-arms, less so for pistols), typical bullet mass and typical bullet charge, and rate of cyclic fire for automatic weapons. From there, you can work out Damage dice, damage type, 1/2D and Max ranges, Bulk, and Rcl.

Assume that RoF is 3 for semi-automatic long arms and double-action pistols, 1 for single-action pistols, and (cyclic rate of fire/min)/60 for automatic weapons. Use stats for similar weapons from GURPS High Tech for single-shot weapons and weapons which must be manually cocked or otherwise readied between shots (e.g., lever action rifles, trombone action shotguns).

Your typical modern pistol will have Bulk -2, with -1 or even 0 for tiny pistols, and -3 for monsters. Rcl will be 1 for easy-shooting guns designed to fire low-powered rounds and/or those designed to minimize the effects of recoil on subsequent shots. Rcl 2 is more typical, with Rcl 3 or higher indicating a gun that wants to jump around when it's fired. Reserve Rcl 4 or higher for brutes with punishing recoil.

Remember that number of shots for SA weapons is limited by mag size, which might be limited by law. Add +1 if the weapon can carry a magazine or clip plus a round in the chamber. For a typical street-legal U.S. semi-auto firearm, assume 10+1 shots. Police and military have access to extended mags of 11+ shots, but bigger mags might increase Bulk and might reduce the weapon's reliability to an unacceptable degree.

Total weapon mass is weapon mass + a full load of ammo + the weight of any magazines, stripper clips, etc. Total reload cost is (cost per bullet x number of bullets) + cost of mag/stripper clip/whatever. GURPS High Tech gives weight and cost stats for most common bullets as well as generic weight and cost numbers for magazines.

Once you've roughly worked out stats for the new weapon, compare it to existing weapons of the same type, caliber, and TL to determine if the new design's stats are roughly comparable. Gun designs are seldom revolutionary, so a particular gun from a given era ought to be pretty close in performance. Guns which shoot the same cartridge with near identical barrel lengths should have virtually identical damage and range numbers.

That last fact makes it fairly easy to design shotguns, since they tend to be close-range weapons with barrel length already optimized for maximum ballistic performance. You can just port over 1/2D, Max, and damage stats from an existing weapon with a similar barrel length, plug in the new weapon's mass and RoF, and then eyeball the new weapon's mass and overall size vs. existing shotguns to figure out appropriate Rcl and Bulk modifiers.

[Icelander]

Originally Posted by Pursuivant

Remember that number of shots for SA weapons is limited by mag size, which might be limited by law. Add +1 if the weapon can carry a magazine or clip plus a round in the chamber. For a typical street-legal U.S. semi-auto firearm, assume 10+1 shots. Police and military have access to extended mags of 11+ shots, but bigger mags might increase Bulk and might reduce the weapon's reliability to an unacceptable degree.

Note that most common magazines for semi-automatic firearms in the US have capacities of 15+ for pistols and 20+ for AR-15/AR-10 type rifles, by far the most common and easily available. Magazines of 15-20 rounds for full-size pistols and 20-30 for semi-automatic black rifles aren't extended, they are the assumed standard.

Under US Federal Law, magazine capacity has nothing to do with legality. Only in some local jurisdictions in the US, very much non-representative in demographic or geographic terms, do there exist laws restricting magazine capacities for weapons and/or requiring that magazines by altered to artifically limit the capacity.

These laws are often named something like 'Assault Weapon Laws' and may additionally regulate firearms based on cosmetic features, whereby the legality of a firearm is determined not by its utility as a weapon of war or tool of crime, but whether it looks scary. This is not unusual in any field of legislation, as rationality is not generally a function of the lawmaking process.

Perhaps the most well-known example are Californian gun laws, but care must be taken not to assume that every state in the US has identical laws and customs to those that hold sway where most of the movies are made.