[WH40K] Imperial weapons numbers

SF: discuss futuristic sci-fi series, ideas, and crossovers.

Moderator: NecronLord

User avatar
Winston Blake
Sith Devotee
Posts: 2529
Joined: 2004-03-26 01:58am
Location: Australia

Post by Winston Blake »

Connor MacLeod wrote:Probably a bit of both. At 8.25mm of course the bullet is going to be bigger (and of course heavier) - assuming dimensions simialr to a 7.62mm bullet its probably about 1.3-1.4 times heavier. If the bullet is even slightly longer it could be 1.5x or more heavier (say 11-15 grams, which is alot for a bullet of that size.)

In terms of muzzle velocity its already close to what the "heavier" 7.62mm rounds do (like the one in the M-14 rifle) and thus it probably gets similar performance.

Assuming ~12-13 gram bullet at 820 m/s you're getting around 4-4.5 kilojoules of KE (nearly 50% more than what the AK-47 does) and ~10 kg*m/s worth of momentum. Some of the calcs with a "heavier" bullet got all the way up to 5-6 kilojoules (nearly 2x effective to modern weapons.)

Range-wise you'd probably be looking at something similar to the M-14 - 500-600 meters at least, possibly up to 800-1000 meters or so depending on scopes and such.
It might be helpful to mention the .338 Lapua round, which is fairly popular for sniper rifles and has lots of information on the net. 0.338 inches is 8.58mm, so the 8.25mm cartridge in question probably has similar performance:
Wiki article above wrote:The loaded cartridge is 14.93 mm (0.5878 in) in diameter (rim) and 93.5 mm long. It can penetrate better-than-standard military body armour at ranges up to 1000 meters and has a maximum effective range of about 1750 meters. Muzzle velocity is dependent on load and powder temperature and varies from 880 to 915 m/s (2887 to 3002 ft/s) for commercial loads with 16.2 gram (250 grain) bullets, which results in about 6525 Joule (4813 ft•lbf) of muzzle energy.
User avatar
Darwin
Jedi Master
Posts: 1177
Joined: 2002-07-08 04:31pm

Post by Darwin »

Winston Blake wrote: It might be helpful to mention the .338 Lapua round, which is fairly popular for sniper rifles and has lots of information on the net. 0.338 inches is 8.58mm, so the 8.25mm cartridge in question probably has similar performance:
Wiki article above wrote:The loaded cartridge is 14.93 mm (0.5878 in) in diameter (rim) and 93.5 mm long. It can penetrate better-than-standard military body armour at ranges up to 1000 meters and has a maximum effective range of about 1750 meters. Muzzle velocity is dependent on load and powder temperature and varies from 880 to 915 m/s (2887 to 3002 ft/s) for commercial loads with 16.2 gram (250 grain) bullets, which results in about 6525 Joule (4813 ft•lbf) of muzzle energy.
Lordy. I would not want to have to try and use that in a full auto rifle. This is the reason the M-14 was not a success. No full-auto controllability. You'd have to be a space marine to keep one on target.
User avatar
Connor MacLeod
Sith Apprentice
Posts: 14065
Joined: 2002-08-01 05:03pm
Contact:

Post by Connor MacLeod »

Winston Blake wrote:
Connor MacLeod wrote:Probably a bit of both. At 8.25mm of course the bullet is going to be bigger (and of course heavier) - assuming dimensions simialr to a 7.62mm bullet its probably about 1.3-1.4 times heavier. If the bullet is even slightly longer it could be 1.5x or more heavier (say 11-15 grams, which is alot for a bullet of that size.)

In terms of muzzle velocity its already close to what the "heavier" 7.62mm rounds do (like the one in the M-14 rifle) and thus it probably gets similar performance.

Assuming ~12-13 gram bullet at 820 m/s you're getting around 4-4.5 kilojoules of KE (nearly 50% more than what the AK-47 does) and ~10 kg*m/s worth of momentum. Some of the calcs with a "heavier" bullet got all the way up to 5-6 kilojoules (nearly 2x effective to modern weapons.)

Range-wise you'd probably be looking at something similar to the M-14 - 500-600 meters at least, possibly up to 800-1000 meters or so depending on scopes and such.
It might be helpful to mention the .338 Lapua round, which is fairly popular for sniper rifles and has lots of information on the net. 0.338 inches is 8.58mm, so the 8.25mm cartridge in question probably has similar performance:
Wiki article above wrote:The loaded cartridge is 14.93 mm (0.5878 in) in diameter (rim) and 93.5 mm long. It can penetrate better-than-standard military body armour at ranges up to 1000 meters and has a maximum effective range of about 1750 meters. Muzzle velocity is dependent on load and powder temperature and varies from 880 to 915 m/s (2887 to 3002 ft/s) for commercial loads with 16.2 gram (250 grain) bullets, which results in about 6525 Joule (4813 ft•lbf) of muzzle energy.
Good point. Works well as an upper limit.

Incidentally, we can also infer that lasguns ought to have at least comparable range to that autogun (probably with greater accuracy over similar ranges, meaning that the effective range of a lasgun is probably also greater). That coincides with a number of sourcees (laspistols having 100+ meter ranges, lasguns having several km+ ranges, etc.)

If we knew what sorts of wounds these put in people, we might be able to make a calc on lasweapons, since lasweapons are supposed to be similar in "effect" to bullets (just with more cauterization/vaporization :P)

Edit: on the other hand, thats a sniper rifle. Alot of sniper rifles tend to be obscenely powerful. (The M-14 has the benefit of being obscenely powerful but also fully automatic as well.) like the 7.62x54mm cartridges used by some like the Russians. Or the good ol' .30-06 :D
Last edited by Connor MacLeod on 2007-06-10 05:47am, edited 1 time in total.
User avatar
Connor MacLeod
Sith Apprentice
Posts: 14065
Joined: 2002-08-01 05:03pm
Contact:

Post by Connor MacLeod »

Darwin wrote:Lordy. I would not want to have to try and use that in a full auto rifle. This is the reason the M-14 was not a success. No full-auto controllability. You'd have to be a space marine to keep one on target.
Not really, just abnormally strong (like Bragg or a Volpone Blueblood stormtrooper.) Hell there are some Guardsman who ware virtually Ogryn (Karnak Skull takers, which admittedly are more a feral regiment, but what the hey.)

There's plenty of reason to believe that your average 40K Guardsman is physically superior in all ways to a modern soldier (bigger, stronger, ,faster, etc.) even if he's not always trained better. This would be matched with a concrurrent ability to handle greater-recoil weaponry.

The scary part is when you consider that some ammo can be "mass reactive' (although admittedly I have only heard of tech-guard using that.)
User avatar
andrewgpaul
Jedi Council Member
Posts: 2270
Joined: 2002-12-30 08:04pm
Location: Glasgow, Scotland

Post by andrewgpaul »

IA vol5 does mention that automatic fireing is wildly inaccurate. So much so that they added a weight at the front of the foregrip, just below and behind the muzzle, to try to compensate for that.

Where does the 'Kantrael'-pattern lasgun name come from? The current rulebook snows the Kantrael-pattern laspistol, but the Cadian lasgun is just referred to as 'M36 Cadian issue'

Steel and Lost Soal, I was wondering if I recognised the story. IIRC, some of the stories in that anthology were reprints from Deathwing, from the Roge Trader era. Don't recognise that one, though; must be newer.
"So you want to live on a planet?"
"No. I think I'd find it a bit small and wierd."
"Aren't they dangerous? Don't they get hit by stuff?"
User avatar
andrewgpaul
Jedi Council Member
Posts: 2270
Joined: 2002-12-30 08:04pm
Location: Glasgow, Scotland

Post by andrewgpaul »

Connor MacLeod wrote:
defanatic wrote:In Inquisitor, hellguns are more powerful lasguns with recharging power packs that you have to carry on your back. It holds more charges than any other type of lasgun (except multi-laser, maybe).
Got a quote/page number?
Yeah, I'd be interested to see that; the word 'hellgun' doesn't appear anywhere in the online Inquisitor rulebook. The closest it gets is the triplex-pattern lasgun with variable damage (at a cost of additional 'ammo' expenditure).
"So you want to live on a planet?"
"No. I think I'd find it a bit small and wierd."
"Aren't they dangerous? Don't they get hit by stuff?"
User avatar
Connor MacLeod
Sith Apprentice
Posts: 14065
Joined: 2002-08-01 05:03pm
Contact:

Post by Connor MacLeod »

andrewgpaul wrote:IA vol5 does mention that automatic fireing is wildly inaccurate. So much so that they added a weight at the front of the foregrip, just below and behind the muzzle, to try to compensate for that.
A recoil compesnator/muzzle brake might also comepsnate for that (some sort of vent designed to redirect the propellant in other directions)
Where does the 'Kantrael'-pattern lasgun name come from? The current rulebook snows the Kantrael-pattern laspistol, but the Cadian lasgun is just referred to as 'M36 Cadian issue'
2003 guard Codex mentions a "short pattern lasgun" manufactured on kantrael. The Eye of Terror codex and website expanded on it, mentioning the "Kantrael pattern" lasgun, which is what the Cadians use. (Kantrael is like a forgeworld or manufacturing world in or around Cadia.)
User avatar
Winston Blake
Sith Devotee
Posts: 2529
Joined: 2004-03-26 01:58am
Location: Australia

Post by Winston Blake »

Connor MacLeod wrote:If we knew what sorts of wounds these put in people, we might be able to make a calc on lasweapons, since lasweapons are supposed to be similar in "effect" to bullets (just with more cauterization/vaporization :P)
You know, I can't find anything on wound ballistics. There's just armour penetration. I guess with an anti-materiel round, stopping power simply becomes a question of 'Did it hit or didn't it?'.
User avatar
Connor MacLeod
Sith Apprentice
Posts: 14065
Joined: 2002-08-01 05:03pm
Contact:

Post by Connor MacLeod »

Winston Blake wrote:
Connor MacLeod wrote:If we knew what sorts of wounds these put in people, we might be able to make a calc on lasweapons, since lasweapons are supposed to be similar in "effect" to bullets (just with more cauterization/vaporization :P)
You know, I can't find anything on wound ballistics. There's just armour penetration. I guess with an anti-materiel round, stopping power simply becomes a question of 'Did it hit or didn't it?'.

Try googling "wound ballistics. I've always found this site to be quite useful.

I'll try cooking up some calcs tomorrow, as I'm getting sleepy (5 am here)

I will note that whilte that IS ballistics gelatin and not actual flesh in those images, the diameters are good for our purposes since the "effect" I go for is largely the permanant wound cavities (IE lasguns making as big a hole in people as bullets do.) They just do it differently.
User avatar
defanatic
Jedi Knight
Posts: 627
Joined: 2005-09-05 03:26am

Post by defanatic »

andrewgpaul wrote:
Connor MacLeod wrote:
defanatic wrote:In Inquisitor, hellguns are more powerful lasguns with recharging power packs that you have to carry on your back. It holds more charges than any other type of lasgun (except multi-laser, maybe).
Got a quote/page number?
Yeah, I'd be interested to see that; the word 'hellgun' doesn't appear anywhere in the online Inquisitor rulebook. The closest it gets is the triplex-pattern lasgun with variable damage (at a cost of additional 'ammo' expenditure).
Whoops. It's in an article on the Specialist Games website.
..http://www.specialist-games.com/assets/FO48InqStorm.pdf

The article has rules for Storm Troopers.
>>Your head hurts.

>>Quaff painkillers

>>Your head no longer hurts.
User avatar
white_rabbit
Jedi Council Member
Posts: 2039
Joined: 2002-09-30 09:04pm

Post by white_rabbit »

defanatic wrote:
andrewgpaul wrote:
Connor MacLeod wrote: Got a quote/page number?
Yeah, I'd be interested to see that; the word 'hellgun' doesn't appear anywhere in the online Inquisitor rulebook. The closest it gets is the triplex-pattern lasgun with variable damage (at a cost of additional 'ammo' expenditure).
Whoops. It's in an article on the Specialist Games website.
..http://www.specialist-games.com/assets/FO48InqStorm.pdf

The article has rules for Storm Troopers.
I think its worth considering that not all the articles on the Inquisitor website are actual official rules, that article for example is written by some unknown Inquisitor fan bloke, its not official.

:wink:
Image
User avatar
NecronLord
Harbinger of Doom
Harbinger of Doom
Posts: 27379
Joined: 2002-07-07 06:30am
Location: The Lost City

Post by NecronLord »

white_rabbit wrote:I think its worth considering that not all the articles on the Inquisitor website are actual official rules, that article for example is written by some unknown Inquisitor fan bloke, its not official.

:wink:
Well, he's not unknown to me, he can (or at least, could until recently, I've not seen him for a while) be found in GW Liverpool.
Superior Moderator - BotB - HAB [Drill Instructor]-Writer- Stardestroyer.net's resident Star-God.
"We believe in the systematic understanding of the physical world through observation and experimentation, argument and debate and most of all freedom of will." ~ Stargate: The Ark of Truth
User avatar
white_rabbit
Jedi Council Member
Posts: 2039
Joined: 2002-09-30 09:04pm

Post by white_rabbit »

NecronLord wrote:
white_rabbit wrote:I think its worth considering that not all the articles on the Inquisitor website are actual official rules, that article for example is written by some unknown Inquisitor fan bloke, its not official.

:wink:
Well, he's not unknown to me, he can (or at least, could until recently, I've not seen him for a while) be found in GW Liverpool.
Cease your quibbling Skinless one!
Image
User avatar
Connor MacLeod
Sith Apprentice
Posts: 14065
Joined: 2002-08-01 05:03pm
Contact:

Post by Connor MacLeod »

Okay;

M-16 bullet

M-16 bullet #2

Both cases the ballistics gel wound is about ~5-6 cm in diameter. ASsuming 15 cm penetration (about what is needed to reach vital organs) the area effected will be about .4 kg

Assuming total vaporization/incineration, this comes out to around 1-2 MJ approximately, ignoring inefficiencies. going for mere "cauterization" with partial vaporization (300 C or so) is about 368 kilojoules. Given the difference between permanant and temporary cavities, I'd say that the former (vaporization) is more consistent. The cauterization would be bound to include temporary (since it will include surrounding flesh as well as what is removed to make the hole.)

Note as well that these bullets DO penetrate straight through, which I am ignoring, and which can affect the calcs (albeit slightly)

7.62x39mm

7.62x51mm

As you can see these bullets "tumble" a bit inside the body, so the wound cavities (permanant) are different. Nonetheless, its about the same mass and thus calc-wise as I did above. I simply included it for comparison's sake. Note, however, that in the case of a tumbling round, the larger diameter of the 40K bullets probably means bigger wound cavities than this.

.308 winchester bullet

buckshot from a 12-gaugeshotgun

These two are roughly consistent in diameters, much larger permanant wound cavies than above.. roughly "fist like" (~10-12 cm in diameter.)

Assuming 15 cm of penetration, that yields around 1-1.5 kg affected by area. Vaporization and incineration yields ~2-3 MJ minimum. Cauterization yields around .9 to 1.4 megajoules.
Post Reply