Silent Ammunition Questions
 

I'm curious as to what weapons can use Silent Ammunition (GURPS High-Tech, p.165). More specifically, my players are looking for options for Silent Ammunition for weapons like the M16 and MP7.

From what's written in High-Tech, it seems that, with the exception of shotguns and grenade launchers which can take normal or silent ammunition interchangeably, a weapon has to be specifically designed for Silent Ammunition.

I only found two GURPS examples of such weapons (1 in High-Tech and the other in Tactical Shooting), and both were pistols. I did a bit of research to see what other examples I could find in the real world, and the only thing that seems to come close are some of the Russian SP rounds, again only for pistols.

On the other hand, I've noticed that GURPS Monster Hunters 1 provides Silent Ammunition as a simple "powder option" available for any weapon, seemingly freely interchangeable with ordinary weapons. That said, I acknowledge that Monster Hunters is a "simplified" set of rules for campaign setting, and thus may not be accurate/realistic when it comes to this.

So I guess my questions come down to, assuming trying to create a "realistic" approach to this (i.e., something that could be done today, in the real world, relatively easily even if not commonly done):

1 - Are there real life Silent Ammunition PDWs, SMGs, Assault Rifles, or even MGs? And what would the GURPS stats for them be?

2 - Can any ordinary weapon use Silent Ammo? Does this require some sort of modification? What would it cost? And if modified, can it then use Silent Ammo interchangeably with normal ammo, or would it only use Silent Ammo until modified back?

2a -> more specifically, as mentioned above, my players are using Colt M16 and H&K MP7, so options specifically for those would be even more pertinent.


Thanks in advance

Re: Silent Ammunition Questions
 

Logically, since going to the trouble of making Silent ammo that isn't subsonic seems silly, it would seem to be a bad match for normally very high velocity rifle or PDW rounds.

Re: Silent Ammunition Questions
 

The issue with using Monster Hunters here isn't that it's "simplified" so much that it's" gloriously unrealistic".

The silence of a silent round comes from its ability to trap gasses inside it the casing. Usually this is done with a piston that is released to push the bullet forward which causes various technical problems in autoloaders. The Russians eventually solved the problem by radically redesigning the whole cartridge and using a spherical bullet because it was shorter.

Simply: if you want a silent M16 orMP7 you'll have to invent a completely new round and a new chamber to hold it.

Realistically people who want to be stealthy load sub-sonic ammunition and attach a silencer rather than play with anything really complex.

Re: Silent Ammunition Questions
 

A bit of clarification as to why the request is being made:

I'm playing a modern-day counter-terrorist/hostage rescue campaign. Every now and then, they come into a group of relatively well trained bad guys who keep their hostages far enough behind the first row of guards that, should a commotion be heard, they shoot the hostages. So, for these particularly tough missions, they want something much more silent.

The group already has subsonic ammunition and the best sound suppressor they can get, used on pistols which are quieter, but sometimes even those gun shots are heard... or it fails to take the tango down (even on a head shot), which gives them time to sound an alarm (typically by shooting back with non-silence rounds). So they want to find something that's quieter, and that packs more of a punch than a suppressed subsonic pistol.


Actually, on a similar note, I presume that Baton rounds are already subsonic by default. I've been applying the subsonic ammunition Hearing modifier to those rounds, and not allowing players to add Subsonic to it. Is that appropriate?

Re: Silent Ammunition Questions
 

Ok, I am going to assume that silent in this case actually means 'no noise at all'- these weapons actually do exist, but are SUPER specific, normally the 'mouse-fart' type suppressed weapon will do just fine in 99% of applications.

This means things like-
The round MUST be subsonic (if it breaks the sound barrier, it makes a LOT of noise)
The round MUST have no tumble ballistics (it would make too much noise whipping through the air)
The weapon itself must prevent basically all escape of expanding gasses
The weapon itself must have all of its mechanism deadened (no click on the trigger, no noise from the hammer striking down, etc)
The weapon itself cannot make any sudden movements (the bolt cannot snap back, it has to move slowly, etc)

The end result is that a completely silent weapon has virutally no penetrating power due to the round not being ideal for delivering energy, and not having much energy to begin with. The weapon itself is very heavy due to all the extra baffling, and the recoil is terrible due to the slow movement mechanics inside, and the rate of fire will be very slow.

1- To my knowledge there are no SILENT automatic weapons, or weapons using any form of ammunition heavier then pistol rounds PERIOD for the above mentioned reasons.

2- Silent ammo is only perhaps 1/4 of the equation, smooth flying subsonic ammunition exists for basically every sort of weapon ( for use with silencers, indoors, varmint hunting, etc); it would probably be easier to just build a new silent weapon then to modify an existing one to be silent. Subsonic and supersonic ammunition are generally interchangeable, but it may be required to change the spring pressures for the two to encourage proper cycling of rounds (The spring would need to be replaced, but could be switched back, the spring is generally accessed during regular weapon maintenance) .

2a- Both basically impossible to make SILENT. Both can be equipped with a suppressor which will make it more quiet, but not silent.

side note: When Monster Hunters says silent; pretty sure they mean 'subsonic' (If you note it says that it it only provides a -5 to the monster hunters hearing check for that weapon see pg 61)

see:
en.wikipedia.org/wiki/Heckler_%26_Koch_MP7

http://www.youtube.com/watch?v=BCzUvCRiBZs

Note that that M16 is still really damned loud (above a capgun), and it jams really easily (could potentially be fixed with a spring change, or perhaps not).

Re: Silent Ammunition Questions
 

Oh, I forgot...

3 - Can Silent Ammunition be combined with sound suppressors for a cumulative bonus with respect to hearing roll modifiers? (I'm guessing no, but have no technical background in this matter)

Re: Silent Ammunition Questions
 

You're not going to get anything quieter than a suppressed subsonic pistol while also getting more penetration. It's just not a category of things that weapons that currently exist. They might like the VAL assault rifle that the Russians made, it fires a heavy, subsonic, armor piercing bullet out of a barrel that is mostly suppressor. High-Tech has it included.

Have they tried using the Mozambique drill on badguys? Coordinated sniper teams? Knives? Doing something to distract the terrorists? Why are these hostage takers so eager to kill the people they have?

Re: Silent Ammunition Questions
 

Yep. So, what would this take? How much would it cost (ballpark)? And could it still use normal ammo interchangeable?


That's what I'm guessing. My players have that already, but are trying to see if they can get something better. I have my doubts, but I'm not the expert, thus the post on the forums...

Re: Silent Ammunition Questions
 

No.

With the exception of shotguns and grenade launchers -- not really. The cartridge case has to be fairly long and straight. The round has to be relatively low-powered. All of this is less than useful in semiautomatic and especially full-automatic weapons.

In fact, this is why it says "Most require a specially designed weapom to fire them" in High-Tech. I put that in there for a reason . . . For the MP7A1 and M16-series? Forget it.

Cheers

HANS

Re: Silent Ammunition Questions
 

You can't do it.

No.

Cheers

HANS