And to repeat myself from another post:

"How can you not like a weapon named after an AC/DC song?" (IMG:style_emoticons/default/grinbig.gif) (IMG:style_emoticons/default/grinbig.gif)

... Now if any character I have gets the gun, I'll have to use AR to have it play part of that song to whoever gets shot at.

That's the first thing that I thought of when I saw the gun, too.

That's the first thing most of us thought when we first saw it. I'm particularly enamored of the Thunderstruck because Thunderstruck is in fact my favorite AC/DC song.

In The Moon is than Harsh Misstress they have than mass driver on the moon fire 100 ton encase in steel weat at earth. It just needed to be encase in steel.

I didn't say that it sould be done, just that it isn't that irrealistic.
If as GM you don't want to allow special gauss cannon ammos it's your right to do so, they aren't in the book and even if they were you could always disallow them if they wouldn't fit into your champain. However if you allow your players PC put their hands on the gauss cannon, the energy packs, and the ammos (all expensive and with an high "F" aviability) than things are certifiably highpowered and a few special pieces of ammo won't make that much of difference.
Also consider that Ex ammo casts 2.5 times the regular one and has an aviability increased of +6 (also if it's "R" it goes to "F"), Ex Gauss Rounds would have a cost of 875 (IMG:style_emoticons/default/nuyen.gif) per 10 shots (easily rounded up to 900 (IMG:style_emoticons/default/nuyen.gif) due rarity) and an aviability of 24 (remember that the cost can be subject to modifiers), it's not going to be easy to aquire nor cheap; and probably the problem is how can the runner keep using a gauss cannon without the army intervening or someone trying to backstab them in order to grab the toy?

Simple: They're working for the army.

What Morrigana said. They just buy a box or two off a corrupt army quartermaster.

Ah, young grasshopper, you qoute Newton's Laws but forget his formulas. Kilojoule to Kilojoule of muzzle energy, gauss weapons have LESS recoil than a similar barrel length chemical weapon.

Why? Gauss weapons have constant (or configurable) acceleration over the entire barrel length while chemical propellants have their greatest acceleration immediately after firing with acceleration decreasing down the barrel length as gas expansion reduces pressure.

For the same experienced peak recoil as a chemical weapon, a gauss weapon can develop much more muzzle energy. If it was a variable acceleration gauss weapon possibly several times more muzzle energy.

Gauss rifles are also functionally silenced as there's no excess powder burn or gas operated loading mechanism. The round is noisy being way supersonic so people hear the shot but its hard to find the shooter. Muzzle flash is also much reduced, if not nonexistent.

In point of fact, there should be NO muzzle flash from a gauss weapon. Muzzle flashes are short-duration burns of the same superheated and rapidly expanding gasses that provide a chemically-projected round with its impetus. Gauss weaponry, thanks to their chemical-less method of propulsion provided by the miracle of electromagnetism, therefore completely lacks any of the aforementioned gasses that would cause muzzle flash. No flash, no sound of an action cycling, although the round will obviously make one Hell of a big bang.

Then again, the Thunderstruck counts as an assault cannon, so it's not exactly small. Sure, they can't find you from muzzle flash, but it must be hard to hide when you're lugging that thing, its heavy-ass tungsten penetrator rod ammo, and some powerpacks around with you. It's the kind of weapon that I'd only use on a run if I'm going to, say, attack the main Lone Star HQ in Seattle.

well, the muzzle flash could be there from heating up of the projectile by wy of air rubbing it the wrong way maybe?
i ain't really sure how fast something has to travel, but i don't think spaceshuttles fall to earth on supersonic speeds and they do glow if i ain't mistaken O.o
and with the bullets being supersonic, you don't hear the actual shot, but the penetration of the soundwall . . hmm, shooter would hear it at his position, target would hear it at their position AND shooter location right?

Muzzle flash is possible from ionization, think static sparks or stun gun arc. Jacob's ladder, given the energy involved. Rail guns are more likely to flashily ionize than coil guns.

And the round leaves a supersonic "wake" that is a shockwave along the entire trajectory. It is experienced as a singular boom to observers at a point in space. If you have enough mics and/or processing power, you can calculate the point of origin (e.g.spatial recognizer) but apply the silenced weapon modifier.

while true, given the amount of time the acceleration happens in, would that basically feel the same to the operator?

we are talking about a acceleration from zero to some multiplier of the speed of sound in milliseconds after all...

I would think that the target would not hear the shot if you hit them right, unless the sonic boom reverberates into the metaplanes . (IMG:style_emoticons/default/grinbig.gif) 9P base is hard to resist on something that is bypassing most of your armor and ripping through whats left.

My rigger has been drooling over on of these for months and now that he has a Vory contact with a connection of 6, I may just mount one on that americar I have been tricking out as main attack drone. (IMG:style_emoticons/default/cyber.gif) (IMG:style_emoticons/default/cyber.gif)

"No one ever expects the Ford Americar!" (IMG:style_emoticons/default/grinbig.gif)

please explain to me how/why the hell you would apply SILENCED WEAPON MODIFIER to a weapon that shoots things that by their sheer speed produce a sonic boom which is strong enough to rattle most in the vincinity?

I suppose that comes from the distinction betwen noice of the shots explosion and the noice of the bullet (or whatever is fired) that breakes the wall off sound; a silencer can take care of the nopice of the explosion but not the one caused by the speed at which the bullet travels (there are subsonic bullets for that). A gauss cannon doesn't use an explosion for accellerating the bullet so that part of the equation is out (I would also add the benefits of elettronic firing), also the noice generated by supersonic objects is dued to the wawes formed by displaced gasses (that can travel at best at the spped of sound) being broken by the supersonic object, the breacking the wave happens for the whole tract of travel the takes place at supersonic speed, in each point of this tract is generated a shockwave that expandes as a sphere, when you hear the shot you are going to hear it coming from the direction of the shortest distance from the supersonic tract of the shots travel, you might need to be deaf to not hear the shot but determining from which direction it was fired is an enterily different story.
Well, at least it's my interpretation.

So probably is the opposition if they were issued with gauss fifles, so some tricked out ammo won't be a problem as the enemy will be outfitted for war. It stands a reason if they are called "Assault Cannons" (also some Explosive Gauss Cannon Rounds might be scarry for infantry but due to economics they will probably be reserved to vehicles).

my adept sniper is pondering replacing his ticked out 9p rifle for one of these or suplementing his aresnal. He's in a merc campaine atm but will need training with heavy weapons to use this right. But as it can have an underbalre anything (normal) weapon montable having that option would be handy as well. Though wether any more anti armor weapons and people with heavy weapon skills are needed is debateable. We have an Orc heavy weapons adept 24 dice with her hmg 22 for her assult cannon. Plus a force 10 free spirt. And 7 morepcs of the same power level.

One thing to keep in mind is the EMP from the railgun as it fires. Any MAD system (or old skool radio system) will give a pretty good paint what with the massive, focused pulse as the weapon discharges.

Another thing to keep in mind is the fact that EX and EX-EX rounds are chemically propelled rounds, not railgun loads. As a railgun round has no casing except for a potential sabot (which really isn't needed if the weapon uses a quad-rail system and a coil built in around the projectile), you can't get added "oomph" from using extra powder (like in the case of RL +P loadings for firearms) and the typically solid, hard material default projectiles make it hard for you to get extra go by using tungsten tips (as in the case of of RL SAP modern military ammo) as an example.

Just stuff to keep in mind for those interested...

There is than limit to how much armour than vechile can carry before it lose manumeile and it have than very slow speed of travel. You cannot have than tank with 32 inches of steel armour. Than tank needed to be able to turn easly have than reason powerful gun and travel with than reason speed. So than man portable gauss rifle is very powerful.

Sigh. Everyone hears "shockwave" and "sonic boom" and thinks it must be house rattling. The "boom" is relative to the volume of air displaced as well as velocity. Plus that "boom" represents energy lost to the atmosphere. Technically energy expended *on* the atmosphere. Point being, its only a fraction of the muzzle energy.

The crack of a bullwhip? The end going supersonic. Not a house shaker by any means and the volume of Mach++ whip is probably greater than that of the gauss cannon round. Given the higher gauss velocity, a bullwhip crack originating at every point along the trajectory is not unreasonable.

Besides, every non-subsonic round already has a sonic "boom" but most people can't separate the supersonic "crack" from the muzzle blast. You need to be very far downrange for the two sounds to be a distinct crack followed by the blast. AFAIK, the only common subsonic round today is .45. Virtually everything else (9mm .22 .38 .44 .357 .50 7.62) is typically supersonic.

Railgun muzzle flash? Answer!

And here!

What Kigmat said.

Dumori, why not get a Gause Rifle with your sniper rifle underbarrel? You can keep using your current skill, and have the armor penetration for when you need it.

That has to be one of the sickest ideas I have ever heard... seriously... evil, in such a good way.

Oh! *smile* Thank you.

It's always been an idea in the back of my mind, since autocannon/gauss weapons are some of the only weapons larger than a sniper rifle. (It was just that before the errata, there wasn't a real reason to do it.)