NEWS

Underbarrel grenade launcher

  • 65 Replies
  • 16762 Views

MijRai

  • *
  • Ace Runner
  • ****
  • Posts: 1845
  • Kane's Understudy
« Reply #45 on: <02-25-16/2105:33> »
They're not all micro-grenades.  40mm is pretty common for the Underbarrel launchers at the very least. 
Would you want to go into a place where the resident had a drum-fed shotgun and can see in the dark?

bangbangtequila

  • *
  • Omae
  • ***
  • Posts: 442
« Reply #46 on: <02-25-16/2137:45> »
They're not all micro-grenades.  40mm is pretty common for the Underbarrel launchers at the very least.

Quote from: SR5 Pg 434
Minigrenades are grenades specifically designed for use
with grenade launchers, set to arm when they have traveled
5 meters from their point of origin and explode on
impact (unless using an airburst link, p. 431).

Unless specifically stated otherwise, I would imagine launchers would all use the modern minigrenade. Old school launchers could use the 40mm, but why on earth would they choose bulk, weight, and just terrible comparative design over sleek, modern, lightweight, and equally effective minigrenades.

YMMV

MijRai

  • *
  • Ace Runner
  • ****
  • Posts: 1845
  • Kane's Understudy
« Reply #47 on: <02-26-16/1104:23> »
Then let's assume 25mm.  And given they're still a projectile with power behind them, put them at 12P flat, no AP.  It is basically a shotgun slug at that point, not a bean bag. 
Would you want to go into a place where the resident had a drum-fed shotgun and can see in the dark?

rednblack

  • *
  • Prime Runner
  • *****
  • Posts: 3225
  • TECH-NO-LOGIC-KILL
« Reply #48 on: <02-26-16/1146:51> »
Then let's assume 25mm.  And given they're still a projectile with power behind them, put them at 12P flat, no AP.  It is basically a shotgun slug at that point, not a bean bag.

I dunno.  Shotgun slugs travel at something like 1200 fps, while grenade launchers send their payload at something like 250 fps.

In general, MijRai, I think you know a lot more about this kinda thing than me.  Can you clue me in on your thinking process?
Speech
Thought
Matrix/Comm
Astral
Subvocal

bangbangtequila

  • *
  • Omae
  • ***
  • Posts: 442
« Reply #49 on: <02-26-16/1239:06> »
Then let's assume 25mm.  And given they're still a projectile with power behind them, put them at 12P flat, no AP.  It is basically a shotgun slug at that point, not a bean bag.

"The bean bag round consists of a small fabric “pillow” filled with #9 lead shot weighing about 40 grams (1.4 oz). It is fired from a normal 12-gauge shotgun. When fired, the bag is expelled at around 70 to 90 metres per second (230 to 300 ft/s)" (Source: Wikipedia)

I would stand by my comparison. There is no way the under-barrel launcher is the same as a purpose built full sized shotgun. Especially since an under-barrel shotgun (Nissan Optimum) deals 10P, I think 10S to reflect it is not designed as a direct weapon but has equivalent inertia is perfectly fair and has the math to back it up.

MijRai

  • *
  • Ace Runner
  • ****
  • Posts: 1845
  • Kane's Understudy
« Reply #50 on: <02-26-16/1303:56> »
https://en.wikipedia.org/wiki/XM25_CDTE

https://en.wikipedia.org/wiki/Neopup_PAW-20

25mm and 20mm grenades, 690 to 1000fps respectively for the low-velocity variants.   Flatter trajectories than your usual 40mm grenade and accurate at point targets up to 500-550 meters.  While slower than a shotgun slug, that's still a multi-ounce projectile (I don't care how 'miniaturized' it is, you're not sticking that much killing power in a warhead that doesn't have appreciable weight) going at around the same speed as a sub-sonic 9mm round.  That is not non-lethal damage. 

Given it fires micro-grenades, I definitely think it would equal the damage on the Optimum at least (I stand by my 12P, no AP statement).  Size isn't that much of a factor in how much damage a firearm does, it's the charge behind the round and the weight/velocity it has when it comes out of the barrel (as well as having a chamber strong enough to safely fire it). 
Would you want to go into a place where the resident had a drum-fed shotgun and can see in the dark?

bangbangtequila

  • *
  • Omae
  • ***
  • Posts: 442
« Reply #51 on: <02-26-16/1332:21> »
I'm on my phone so I don't have formatting options, but this is the m203 40mm under barrel launcher, ubiquitous with grenade launchers, listed at 240 m/s
https://en.m.wikipedia.org/wiki/M203_grenade_launcher
The XM25 is not a launcher. It's an airbursting shell. In my opinion it is more comparable to assault cannons, or a specialized weapon not listed. Easy to make an equivalent using airburst links though, I guess.

It's very much what you imagine it to be in your games. In my opinion, I don't see an under barrel launcher beating some assault rifles in physical damage. It just doesn't make sense to me in terms of narrative, and would ruin opportunities for really cool, cinematic gameplay. You may prefer a more lethal interpretation in your games, and that has some basis. As always, the rules are an aid to gameplay, and if they start to hinder your storytelling then ignore them.

rednblack

  • *
  • Prime Runner
  • *****
  • Posts: 3225
  • TECH-NO-LOGIC-KILL
« Reply #52 on: <02-26-16/1350:26> »
So would a char get a defense test against getting hit by the projectile itself?
Speech
Thought
Matrix/Comm
Astral
Subvocal

MijRai

  • *
  • Ace Runner
  • ****
  • Posts: 1845
  • Kane's Understudy
« Reply #53 on: <02-26-16/1747:10> »
240m/s is much faster than your initial 70-90, and is definitely capable of causing lethal damage given the size of the shell. 

The XM25 is explicitly a grenade launcher, it is just designed with airburst shells in mind.  You can get Airburst as a weapon upgrade for all launchers for 600 nuyen at only 6R Availability.

Why would a grenade launcher not beat a rifle's damage?  It's firing a projectile between five to eight times the size of a normal bullet at a somewhat slower velocity.  That much mass accelerated that much should cause a notable amount of damage, before it detonates.  We're not even talking about after the grenade hits, when that explosion just floors anything that isn't heavily armored and/or a buff troll.  The limitation being you can only carry so many grenades and the risk of possible collateral damage.  And how does that ruin coolness or cinematic gameplay? 
Would you want to go into a place where the resident had a drum-fed shotgun and can see in the dark?

Herr Brackhaus

  • *
  • Prime Runner
  • *****
  • Posts: 3041
« Reply #54 on: <02-26-16/1759:11> »
Anecdotal only, but the only times I've heard of a fourty mike mike actually killing someone by (unintentionally) hitting a target cause of death has been head trauma.

A 40mm grenade is propelled out of the barrel quickly as indicated by the above muzzle velocities, but keep in mind that it also loses velocity, and thus kinetic energy, significantly faster than even a subsonic bullet because of the mass of the projectile itself. Also keep in mind that unlike a bullet shaped to penetrate and with enough energy to actually do so, while a modern day 40mm grenade has a much larger surface area and so would need an equally significant velocity to penetrate a soft target; gunshot victims die from shock trauma or exsanguination more often than not, and a 40mm hitting you in the chest (especially if you're wearing armor) is therefore more likely to inflict Stun damage in my opinion. The exception would be headshots, of course, as a knock of that kind to the noggin would probably put you in the grave from blunt force trauma to the head.

If you ask me, getting hit by the Shadowrun microgrenade should only be lethal in the absolute worst case situation, meaning critical glitch; it's by definition an unlucky course of events. I'd liken the projectile more to a bean bag round than a slug, and give it a lower damage code but some special rules for what happens on a glitch or critical glitch, personally. There is such a thing as too much realism, and I'd draw the line at microgrenades inflicting shotgun-level damage.

So would a char get a defense test against getting hit by the projectile itself?
That's how I handled it the one time it came up; the player rolled his attack as normal and got enough hits to land his grenade on the target without scatter, and then the NPC rolled defense against the attack. He failed, took 6 stun modified by damage resistance, then had to resist the explosion of the proximity trigger grenade which blew up when the grenade hit.
« Last Edit: <02-26-16/1801:59> by Herr Brackhaus »

Duellist_D

  • *
  • Chummer
  • **
  • Posts: 223
« Reply #55 on: <02-26-16/1906:52> »
Totally different approach:
I'd rule the damage (non realistic as it might be) pretty low, because having a cheap and easily available high damage - high range underbarrel weapon that can be used for both precise and multiple effect wide payloads would rival normal weapons way to much.

bangbangtequila

  • *
  • Omae
  • ***
  • Posts: 442
« Reply #56 on: <02-26-16/1911:46> »
Sorry like I said I'm on my phone. The m203 is listed at 250 fps. I apologize for my mistake, you can verify through the link I provided earlier.

Rooks

  • *
  • Omae
  • ***
  • Posts: 992
« Reply #57 on: <02-26-16/2055:10> »
True old sun editions the shock glove hand physical damage from Unarmed on top stun damage from the glove now it's just stun

Adamo1618

  • *
  • Guest
« Reply #58 on: <02-29-16/1127:52> »
How about you subtract 1 DV for each range band? Air resistance is roughly proportional to the square of the radius, meaning bigger grenades are going to slow down quite quickly. Meaning like 12P at short range, 11P at medium and so on.

MijRai

  • *
  • Ace Runner
  • ****
  • Posts: 1845
  • Kane's Understudy
« Reply #59 on: <02-29-16/1444:27> »
I was saying -2 earlier. 
Would you want to go into a place where the resident had a drum-fed shotgun and can see in the dark?