I do not write down every little detail of how the weapon will work because I do not want to make a huge wall of text for piecewise. I know there are things I haven't covered in my description, like, for example, how is the cradle suspended so that it doesn't impact the walls of the barrel or how can it be reset when a projectile of increased mass causes it to lag behind. If piecewise has a problem with part of the weapon, then he will let me know and I'll be able to provide one of the solutions I have thought of. If piecewise doesn't object, then I just assume I have somehow made the weapon work, since it doesn't explode during test-firing.
Sorry to the anonymous commenter if I sounded harsh, I just find hidden criticism like that annoying, because if piecewise hadn't posted that, then I would have no chance to respond. Plus the fact that I don't like writing large walls of text/arguments when I'm busy, but that's hardly the commenter's fault.
Now, on to responses:
First, you need it shaped at least like a proper bullet or artillery shell for any accuracy beyond that of a smoothbore cannon.
Well, of course. One would think that the fact that its name contains the word Slingshot and that it's made as a "launch almost anything" weapon and the fact that I actually mentioned loading cannons with improper ammunition in it would make it apparent, but if you feel the need to state the obvious, then go ahead. Still, the fact that it can launch non-aerodynamic ammunition doesn't mean that it can't launch properly constructed aerodynamic ammunition, a fact that was also mentioned in my post.
Secondly, due to the nature of gauss propulsion, the projectile needs to be both paramagnetic and balanced by mass or it'll rip apart during the acceleration, which could damage your gun and it's wielder pretty well.. and just eyeballing it is not accurate enough. That's not quite as big an issue with a ship-sized gauss cannon, as it's robust enough so that it will get the object out of the barrel, but it'll be leaving in a large number of pieces.
This is also a part where the commenter failed to read the weapon description properly. If they had, they would have noticed that:
a) The weapon does not require its ammunition to be magnetic. It CAN fire magnetic projectiles by functioning as a normal Gauss Rifle, but that's not all it can do.
b) The weapon has the problem that something fragile put in it will break apart during acceleration or when it contacts the air. There are two obvious solutions: Don't put fragile things in it and use the power setting to lower the speed/acceleration of the projectile. Same as putting non-aerodynamic things that could tumble inside the barrel and get stuck. If you can't figure that out, you probably shouldn't be handling this weapon.
Railguns and coilguns are powerful devices. If he wants a gun he can just shoot random objects out of, he should be looking at smoothbore cannon, and he needs to remember cladding and wadding are not optional. Railguns and coilguns are fundamentally different.
That's not what the weapon was designed for. Cannons require gunpowder. Gunpowder requires resources. This weapon is designed to function with as little resources necessary as possible, while allowing a large variety of ammunition to be launched. It's like a laser working off a generator that allows it to have infinite ammo, only this one has the strengths of the Gauss Rifle: It can launch specialised ammunition like Grav-Shot or other kinds of Ani-Tank Gauss Ammunition and it can launch non-magnetic ammunition designed by the wielder.
Also, what does cladding mean? I think it means to put a layer of metal on top of something but I don't understand what it means in this context.
Still, whoever did is correct is correct about how insanely dangerous that thing would probably be, with the ease with which it can damage and destroy itself (here's something the comment didn't mention - damage to the coils (which is basically inevitable with the way it's intended to be used) could potentially result in a magnetic IED). And the accuracy comment too. As Syv said - you'd probably be better off getting a small(-ish) vector automanipulator and a barrel that's functionally similar a smoothbore cannon barrel
I don't understand why damage to the coils would occur. Which part of the weapon would damage the coils?
And vector manips go against the spirit of the weapon. It's meant to be a multi-purpose tool rather than a pure weapon that can be cheaply mass produced and given to civilian forces/sod commandos/infiltrators that could end up cut off and without supplies. They would be given along with some more powerful ammunition like grav-shot or red-shot or those chemical gauss rounds that can eat through battlesuit plate, which the wielder would be instructed to try and conserve for emergencies. They could be given along with generator fed lasers with various helpful features and some other basic medical/engineering/communication supplies as a sort of "starter pack" for civilian armies, along with the more conventional and more powerful weapons that will be created in greater numbers and given to regular armies. A vector manip would mean that the weapon would be very expensive, require manipulator batteries and there would be no variable power setting (so that things like launching a grappling hook or spear or grenade from it would be impossible, greatly reducing its versatility). The fact that it can be used for those crazy projects most inmates sometimes build is an added bonus (like that one guy who tried to build that kinetic-amp-tipped-stake launcher).
The biggest problem with that design is that it won't be able to launch anything magnetic, because whatever it is will move with the cradle.
The cradle can be locked in place and the coils unlinked so that the weapon functions like a normal gauss rifle.
The cradle itself is also likely to break apart spectacularly because of the forces involved in sudden acceleration of something very heavy and not perfectly braced against the cradle.
Simple solution: Add padding.
And lower the power setting so that you don't try to throw supersonic, irregularly shaped rocks at your enemies. If you're throwing rocks, you're probably either targeting fleshy things at really close range or are out of ammo and really desperate because you are trying to damage the cameras of the battlesuit advancing on you with rocks. And, well, if you're that desperate, damaging your weapon is the least of your problems.
A way to judge the type the ammunition inserted so that the best power setting can be selected would be best, but that would probably get complicated and require cameras and electronics and maybe some kind of spectrometer. So just a number of preset power settings with clear meanings would be best (from launch a ball to your friend all the way to Full Power)
And remember, the cradle only gives ammunition half (or less, due to its mass) the acceleration of a normal gauss rifle in the best case scenario because of the way it operates.
The easier way to achieve what you want is something like a gauss ballista - two discrete acceleration rails in parallel, with a sturdy pusher plate embedded inbetween and linked to permanent "projectiles" within the rails - though obviously the rails won't enclose them completely because a slit is needed to slide the pusher plate along. This way the gauss rails will work in their normal circumstances, on "projectiles" that will easily comply with the magnetic forces, without affecting the actual projectile.
Yeah, that's actually a very good idea. It would solve the deceleration problem when launching not-as-magnetic-as-the-cradle objects. And probably increase the power output a bit and decrease maintenance. But less pusher plate and more Π shaped, so that aerodynamic ammunition put in it would point forward and be generally easier to align with custom ammunition. Only problem I see is that then you wouldn't be able to launch magnetic projectiles like a gauss rifle that way, which is one of the features of the weapon.
Other thoughts:
An adjustable cradle size would be best, since it would ensure the ammunition will remain in place and keep pointing in the right direction. Auto-adjustable would be even better, but that might be more complex.
I could also make the barrel a bit bigger to account for whatever launched inside it tumbling.
I'd also add a plasma window (it's not like our generators lack the power to do that) and some vacuum pumps to prevent the problems arising from air resistance inside the barrel (although the cradle pushing the air inside forward would help with that) but that would make the weapon too complicated and I'm trying to design something relatively simple, relatively low maintenance that doesn't require lots of supplies to function, but with multiple uses.
Anyway, all that is for later. I just wanted to get an OK from piecewise that the basic concept works.