[WH40K] Imperial weapons numbers

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Winston Blake
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Post by Winston Blake » 2007-06-10 04:59am

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.

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Darwin
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Post by Darwin » 2007-06-10 05:14am

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.

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Connor MacLeod
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Post by Connor MacLeod » 2007-06-10 05:34am

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.

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Connor MacLeod
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Post by Connor MacLeod » 2007-06-10 05:42am

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.)

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Post by andrewgpaul » 2007-06-10 05:48am

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.
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Post by andrewgpaul » 2007-06-10 05:54am

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).
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Post by Connor MacLeod » 2007-06-10 05:57am

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.)

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Post by Winston Blake » 2007-06-10 06:26am

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?'.

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Post by Connor MacLeod » 2007-06-10 06:38am

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.

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Post by defanatic » 2007-06-10 07:32am

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.
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Post by white_rabbit » 2007-06-10 12:50pm

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:
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Post by NecronLord » 2007-06-10 02:50pm

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.
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Post by white_rabbit » 2007-06-10 05:39pm

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.
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Post by Connor MacLeod » 2007-06-12 04:08am

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.

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