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Old 12-10-2017, 10:27 AM   #1
RedDragon
 
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Default Questions about High-Tech/Ultra-Tech Gun Interactions.

So, the title should explain the basics. I'm mostly interested in weapons, and guns in particular. Being an amateur firearms enthusiast (and a somewhat less amateur sci-fi enthusiast) myself, I've picked up Gun Fu, High-Tech, High-Tech: Adventure Guns, both of the High-Tech: Pulp Guns books, Tactical Shooting, and most of the relevant Pyramid editions (including Military Sci-Fi, which is fantastic, BTW). I've just been wondering how ammunition types and accessories from High-Tech and Tactical Shooting work with the guns from Ultra-Tech. I'm worried less about caseless and ETC guns than I am about Gauss Weapons. Of course, as the GM, I could always just arbitrarily lay down the law, but I'd like some outside clarification on both the RAW and the RAI. Ideally, I'd want someone with a pretty good understanding of both ballistics and firearms (including theoretical near-future developments in those fields) and the GURPS rules, but someone with one or the other would be helpful too. I understand that all these weapons are just extrapolations and may not work as presented in Ultra-Tech, but some sort of instruction would still be great.

With that out of the way, here goes:
Silencers (HT and TS): Are these able to be used with Gauss Guns? Would they even have an effect?
Flash Hiders (TS): Would it be reasonable to assume that these are still standard on the guns from Ultra-Tech? Would Gauss Guns even need something like this?
Compensators and Muzzle Ports (GF and TS): The descriptions for these mention venting the firing gas. Does that mean these wouldn't work on Gauss Guns?
Slide-Locks (HT): Less of an Ultra-Tech question and more of a general one. Would it be feasible to have a "switchable" slide-lock? (as in, you flip a switch and the gun becomes a manual repeater)? Would a Gauss Gun benefit from such a device?
Ammunition (HT, TS, UT): This was my main question. High-Tech has a massive list of ammunition types, and I was wondering as to the feasibility of using some of them in Gauss Weapons (and to a lesser extent in caseless and ETC guns). Specifically, those that mention modifying the propellant, such as Subsonic Rounds, Match-Grade and +P Bullets, etc. Also, RAW I believe that APFSDSDU rounds (for example) are capable of being used even in some of the medium-sized caseless handguns from Ultra-Tech. Is this RAI? Can APFSDSDU rounds be used with Gauss Weapons?

Much appreciated.
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Old 12-10-2017, 10:38 AM   #2
AlexanderHowl
 
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

Realistic gauss weapons deliver payloads at 10 times the speed of conventional weapons, so they cannot be silenced and cannot have their flash hidden (the flash is from the plasma trailing the projectile in an atmosphere). Since they do not use gases for propulsion, they cannot use venting systems to reduce recoil. I would rule that the ammunition listed in High-tech would fragment at the velocities of a gauss weapon, so I would suggest using the superior ammunition in Ultra-Tech.
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Old 12-10-2017, 11:05 AM   #3
Fred Brackin
 
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

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Originally Posted by AlexanderHowl View Post
Realistic gauss weapons deliver payloads at 10 times the speed of conventional weapons,
Physically possible railguns can reach that speed but practical designers would avoid it. The target speed for the railguns the Navy is developing is "only" 2200 meters per second which is just below the level where the projectiles would start burning up like little meteors.

That's also just below the speed at which even the toughest depleted uranium or tungsten projectiles would explode on impact.

If you search for videos of railguns in action you'll see them spitting out a huge ball of fire when like a tank gun firing. So no hiding or silencing that.

However, there is a different sort of electromagnetic gun called the coilgun. It has lower velocity potential and there are technical issues with maxing out their power but for the mature TL10 Gauss guns coilguns should probably be assumed. Note, do not take the use of "railgun" in any particular weapon in UT literally.

Coilguns have no propellant gasses so there's nothing to hide or silence and nothing to vent. so none of that applies.

The Gauss guns in UT are already using a sort of high density ammo as default (except for the shotguns and grenade launcher types) so their penetration generally can not be enhanced by ammo choice though special effects such as explosive damage can be achieved for large caliber gauss guns.

UT has its' own selection of ammo and there is generally nothing from HT that I'd bother with. The option in HT for Very High ROF would be useful and currently isn't in UT.
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Old 12-10-2017, 11:17 AM   #4
Ulzgoroth
 
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

An essential initial understanding: Ultratech came out before High Tech, and was written without reference to High Tech. It has some issues with purported 'future' gear being outperformed by historical gear as a result.

Now, on Gauss guns - Gauss guns are not firearms, and in many respects do not behave anything like firearms. You certainly can't modify their propellant. On the other hand, you can by RAW vary their firing velocity, as stated on UT141 with reference to UT139. Note that this means that RAW, you can fire subsonic Gauss rounds, and only suffer half damage as a result! This is utterly nonsensical, but it is in the book. You use the same ammo for high and low power gauss shots, it just uses up more or less of the power cell.

They shoot quite small, hypersonic projectiles - you can't plausibly make them quiet without also making them useless and there shouldn't be any specifically muzzle-associated blast or flash to hide. (The railguns probably do have muzzle blast and flash from vaporized driving material, but not the gauss guns.)

Ammo types for EM guns are a bit of a pickle. It's almost certain that they're already shooting sabotted projectiles of some type (explicit for rail guns) so how and whether to modify the stats for other ammo isn't particularly clear.

As for slide locks, EM guns probably have powered actions - there's really no benefit to having a recoil-operated action when your entire gun is a useless brick without power, and most of them are low-recoil besides. If that's the case, would be a trivial software feature to be able to switch the action to only feed a new round on command.
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Old 12-10-2017, 11:18 AM   #5
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

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Originally Posted by Fred Brackin View Post
However, there is a different sort of electromagnetic gun called the coilgun. It has lower velocity potential and there are technical issues with maxing out their power but for the mature TL10 Gauss guns coilguns should probably be assumed. Note, do not take the use of "railgun" in any particular weapon in UT literally.
UT is quite expressly using it literally - and explicitly distinguishes that 'Gauss guns' are coil guns.
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Old 12-10-2017, 11:27 AM   #6
RedDragon
 
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

I'm sorry, I should have clarified; I'm using the optional rules for EM guns from this forum post: http://forums.sjgames.com/showthread.php?t=147082

So Gauss guns have the armor divisor dropped and their base damage increased. This makes it an upgrade to use other bullets, rather than a downgrade.
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Old 12-10-2017, 11:31 AM   #7
Ulzgoroth
 
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

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Originally Posted by RedDragon View Post
I'm sorry, I should have clarified; I'm using the optional rules for EM guns from this forum post: http://forums.sjgames.com/showthread.php?t=147082

So Gauss guns have the armor divisor dropped and their base damage increased. This makes it an upgrade to use other bullets, rather than a downgrade.
Well, since that explicitly says that discarding-sabot options can be added on, that's clear enough.

Using HT ammo rules with UT is still a bit inherently fraught because, as noted, UT was not written with any reference to HT and stuff just doesn't line up. But that does make the general EM ammo issue less of a mess.
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Old 12-10-2017, 11:56 AM   #8
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

Coilguns could easily be tuned to fire sub-sonically, and the firing is not innately loud. I don't see any reason why a coilgun couldn't have a "stealth mode" setting.

It would do way less damage, and probably switch from piercing to blunt, but it's conceivable it's still useful.
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Old 12-10-2017, 12:19 PM   #9
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Default Re: Questions about High-Tech/Ultra-Tech Gun Interactions.

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Coilguns could easily be tuned to fire sub-sonically, and the firing is not innately loud. I don't see any reason why a coilgun couldn't have a "stealth mode" setting.

It would do way less damage, and probably switch from piercing to blunt, but it's conceivable it's still useful.
Subsonic firearm bullets still do piercing damage, so I don't think subsonic coilgun shots would differ there.

But a 4mm coilgun round weighs 2.7 grams. That's just above the heavy end of typical .22 bullets (says wikipedia), which are normally at least a little supersonic. So...about as useful as a silenced .22, perhaps. That's not nothing I guess, especially from the pistol or SMG frames.

EM grenade launchers should probably be fired subsonic more often than not, since payload rounds don't usually need impact damage. If their base firing mode isn't already subsonic...
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