New system for firearms, Slight adjustment to the way they work Options

[Cweord]

For years I have been bugged by the fact that Shadowrun guns seem to do range by ammo type and damage by gun (it's close to the reverse in the real world, though caliber does have some effect on range).

So I have reversed it, and am writing up a way to stat range by barrel length (with items like stocks, bipods & forward grips modifying it) and damage by caliber (this is giving me a little trouble with the new AP system, as I cant get hold of reliable penetration data - the nice large FBI archive is only available to law enforcement)

For damage, the amount of damage is fairly similar, and the ranges fit in to similar brackets for the standard weapons (I have based most on modern equivalents for barrel length)

Some of the SMG's have had a major range cut down, due to lack of stock, for grip or tiny barrels (the Ingram Smartgun isn't the only gun to go for now). This system adds more variance between guns, makes sharing ammo between caliber type more practical.

Just to be really nasty, I am using the glitch system (similar to gremlins, cursed etc) to add a reliability system to all equipment, including guns.

I havn't written this up as much more than notes for my self at the moment, though if people are interested I will right it up fully and post it.

Equally, if anyone knows where I can get some reliable penetration data for the most common ammo type I would be greatfull, if not I will have to do it by the grade of ammo and that is not as variable.

[kzt]

Penetration of what? RHA? Concrete blocks? Sandbags? Kevlar layers?

[Cweord]

the FBI data has the penetration of different calibers through various items, starting from ballistic gel, adding clothing then going up in different types of armour.

I would just be happy with different rounds going through the same number of layers of kevlar. I can find some of this in advertising for a few rounds but nothing that covers a wide veriety

[Thufar_Hawat]

I would be very interested in any thing you come up with.

Ash

[Cweord]

I am currently causing my brain to leak out of my ears to work out an empirical system to calculate damage based on the weight (to counter size) and muzzle energy of a bullet.

I was just going to use muzzle energy but to quote (just not sure who)

"a 9mm may or may not expand, a .45 will never shrink"

as there is no variable on damage, I am trying to incorporate this in to base damage.

Range's are done, just need a little tweaking (I.E the effects of APDS and bipods on range).

[Cweord]

OK, Damage (with out ap) = ((weight of round x5) + (Muzzle Energy/20))/20 +2

This makes weapons more dangerous, but you can change the +2 to +1 to get closer to the original. Higher Calibers though are a LOT more dangerous eg .50AE comes in at 12.

With the Uber calibers (Anti Material Weapons) the damages were a little out of control with that math, so I put in an energy cap at 2500j on rounds over 4000j on the grounds rounds that size would probably carry right through the body.

I have also added a personal rule that for every 250m the weapon damage drops by one, due to loss of energy (shouldn't happen that often at the ranges that are usually involved) but it means that .50BMG is down to 14 at 1500m

Please note, these damages are not supposed to be uber realistic, but have been worked out to fit in to the game system roughly as designed (so you are not likely to kill on one shot unless you are good, with a high caliber weapon).

When I have the information I need to do ap, I will do a list by caliber. Ranges to come shortly

[Ed_209a]

If I were going to redo the firearm damage system, I would base the stats on the bullet, then modify it by the barrel length, then weapon features.

For example:
X-Light Pistol (.22) 2P/0AP
Light Pistol (9mm) 3P/0AP
Hvy Pistol (.45ACP) 4P/0AP
X-Hvy Pistol (.44Mag) 5P/0AP

Light Rifle (5.56mm) 5P/-3AV
Rifle (7.62mm) 6/-5AV
Heavy Rifle (.338 Laupa) 7/-6AV

Then you have barrel length:

Short (Less range, dam & pen)
Standard (4-6" for pistols, 15-20" for rifles)
Long (More range, dam & pen)

[Cweord]

Though barrel length has some effect on damage, it's not huge, the size of the round and the amount of energy it delivers have far more effect (and with such low damage totals, the barrel length is not likely to adjust it - I looked in to it).

What barrel length (and velocity) do have a large effect on is Range, so all my ranges are based on that - though for simplicity's sake only 2 different velocity types, with 500mps being the change over point (that separates Pistols and Rifles).

To take sniper rifles in to account I have included acurisation, with sniper rifles being assumed to have the maximum level at manufacture (hence the exorbitant price).

The reason I didn't use the ranges for the damage modification on range, is that it would be overly prohibitive on the short ranged weapons, and unrealistic.

Barrel Lengths for range are far more detailed that 3 sizes, it works in inches from 1 - 32

[Cweord]

Pistol Caliber
Round Dam
.22 3P
.38s 5P
9mm 5P
10mm 7P
.45 ACP 7P
.357 Mag 6P
.44 Mag 10P
.50 AE 12P
.40 S&W 5P

This covers the most popular modern Pistol calibers, with recoil mods increasing on the larger ones (memo to me, must work on that).

The pistols with the P90 and MP7 rounds aren't included here as they use rifle ballistics.

[Kyoto Kid]

...OK so how would a Ruger Super Blackhawk (Super Warhawk) 10.5" barrel, firing a .44 mag round stat up?

[Cweord]

0 - 5 6 - 25 26 - 45 46 - 85

For Ranges


44 Mag comes in at 10P (it is a big round with lots of energy)

10.5 comes between the 2 sections so I have used the lower for ranges.

It would also have a +1 recoil mod due to the power of the round

[Kyoto Kid]

...so basically it loses it's -2 APP but gains in +4 in DV. That's a pretty nice trade off. Since it is a SS weapon, the recoil would effect every shot fired correct? (I've fired a Super Redhawk before and noticed the kick was not as bad as shorter barreled revolvers firing the same round. Of course I was gripping it two handed).

[Cweord]

AP hasn't been done yet, I have no decent data to work from, I would expect 1 or 2 in AP though.

The kick would only effect the second round + fired as the round would have left the barrel before the kick of the first could take place.

I am working of more advance recoil rules as well, but they will come in later, as will reliability rules (which the Super War Hawk would do very well in being a revolver).

[Kyoto Kid]

...being that the Super Warhawk is only a SS weapon (meaning only on shot per IP) the recoil would then not come into play.

10P with -1 to -2 AP makes this an extremely dangerous gun (as it should be). With this, the "Short One" can make that Troll Mage say more than "Ow!".

I wince just thinking at what the PJSS and Sniper Rifles will do.

[kzt]

It's a lot more complex than weight and muzzle energy. Area of the bullet, cross-sectional density, etc. Factors that work in handguns don't translate well to rifles as you start getting effects due to velocity. And identical weight and shape bullets with different characteristics will behave completely differently. A 7.62 mm NATO US vs German has totally different terminal effects (as the German round fragments) and the 7.62 mm Jacket Soft Point is hugely more effective than either of them. It's a hard problem.

A few suggestions:

FBI Handgun Wounding Factors and Effectiveness

"Bullet Penetration: Modeling the Dynamics & the Incapacitation Resulting from Wound Trauma" by Duncan McPherson http://www.firearmstactical.com/bulletpenetration.htm


The requirements by the FBI for penetration are well know. Several of the major ammo manufactures run wound ballistics seminars for LE.

3 reports here
http://www.le.atk.com/Interior.asp?section...s/downloads.asp

Eval tool here
http://www.winchester.com/lawenforcement/t...ng/testing.aspx

See also
http://www.tacticalshotgun.ca/ballistics_shotgun.html


For armor penetration you could poke at the v50 data for body armor. But armor penetration is also complex. I've seen tables on the web showing typical RHA penetration of US rounds, but I can't find them now.

[Cweord]

Thanks for the links,

I know there not that similar, but you have to draw the line between realism and practicality somewhere, and Shadowrun isn't a hyper realistic system (thank god, having played millenniums end which is).

Using those 2 factors gives a relatively easy way for anyone to stat ammo, with out having to search out details on detailed wounding and penetration dynamics. If your not worrying about wound location - why go that far in to wound dynamics.

In that kind of detail you would have to add tumble, spread and work off transfered energy not muzzle energy (which again I don't have detailed stats to work from).

Equally all the stats so far are for standard 'ball' Ammo, JSP, JHP etc would all have different modifiers, though APDS will effect the range due to the hypersonic ammo.

I am open to any ideas though - I am in the UK, so I don't have huge access to firearms.

Equally if anyone has any stats on round penetration through Kevlar or amour of any sort (preferable for mulitple types of round) I would be greatful, I would like to be as thorough as possible whilst keeping the system practical.

[kzt]

[Kyoto Kid]

[hyzmarca]

If you modify the damage codes of weapons it is also necessary to modify armor values, or risk getting wonky results. At 10P, a Ruger Warhawk can reliably make armored vehicles explode.

[Cweord]

Yes, but that ratio is screwy, light weapons should not be able to take out vehicles that easily, it should be able to punch a hole in the side of a vehicle, and if it's only Kevlar armour then maybe punch through it. It's not going to go through 1 inch armour plate though.

The system is designed for characters, there are multiple problems with the vehicle system atm, but as I have no riggers in my group I am working on other things first.

And I know it is not the most efficient way to calculate damage - but if you have a better suggestion I am willing to listen. I have done the best I can think of with information that is easily accessible.

[Wounded Ronin]

[kzt]

[Cweord]

Kzt,

Do you know where I can get a copy of these details, I am more than happy to do some re working if I have some usable data.

Preferably a summery as I don't really have time to read through huge reports.

and I agree with ignoring CNS and organ damage, thats where extra damage from the roll comes in.

Still searching for some unified armor penetration data, I have done a lot of searching but found little that works together. I may just end up picking arbitrary numbers at this point (which would be disappointing)

[kzt]

It's from McPherson's book "Bullet Penetration" 1st edition. I'd suggest trying a large library, like a university library or a military/major police dept.

The basics are just a set of equations for solid bullets in which the only significant factors turn out to be bullet diameter and shape, with penetration depth as a secondary factor. Bullet energy has no impact on damage, and weight and speed have impacts only so far as they ensure it has enough penetration. It's more complex when dealing with expensing bullets, but it's still not directly linked to energy or velocity at all.

And he doesn't really discuss rifle bullets at all other then to point out that starting at the 2500-3000 FPS range the temporary cavity produced exceeds the tissue elastic limit and does contribute significantly to wounding effects.


A good source for non-technical penetration data is http://www.theboxotruth.com/, which is by a guy who goes out and shoots stuff to see what happens.

A useful page on US weapon ammo (including penetration data where available is Gary's U.S. Infantry Weapons Reference Guide, which is the one I couldn't find last night.

As a starting point for thinking about armor penetration against body armor look at Protection Levels of Ballistic Body Armor

[Cweord]

Thankyou,

Don't think a library over here will help though, the lack of a major gun culture means that there isn't much literature available (the best I might find is a Jane's Ammo, and I already have that)

I will look in to those online resources though