What reason is there for a combination Chemical/Electrical gun?
Sure, you could build a conventional chemically powered gun with black powder and everything, and then further accelerate the bullet with a coilgun at the end... but my initial thought was that this would be needless complex. Would there be any advantages to using both types of propellant to contribute 50% of the firepower over just making a weapon that gets all its firepower from one type?
To answer this, I went to check out if such a thing already exists IRL. If it does, then someone probably built it because there is some use for it.
BUT, no such weapon seems to exist.
I did find this patent though: https://patents.google.com/patent/US20160341514A1/en
This patent is for a chemically powered gun, that vents some of the gas into a second tube to power a second gun. The second gun's bullet passes through coils which slows the second bullet, and provides some extra thrust to the first bullet through a coil-gun assembly at the end of the first gun. This seems massively inefficient and complicated. Certainly as shown in the patent, it would be better to just make a gun that can accept a larger bullet and use all of that propellant for the bullet instead of losing a lot of your power by all the conversion steps that need to happen.
Trying to think of applications, perhaps you could use this idea to get more distance out of a single ammo type. For example if all you have is one type of bullet, you could load two into your gun and use one bullet's energy to power a coil-gun to further accelerate the other bullet. You could also scale that up to use 10 bullets to power one bullet. This could turn a stockpile of regular rifle ammo into more of an armor-piercing projectile... BUT This is a lot of added complexity and a very heavy system when compared to "Just using a gun with a bigger bullet".
My second thought was "Maybe there is some use in using a coil gun at the end of a regular gun to help precisely control the speed at which the bullet leaves?" Of course that doesn't make much since because why wouldn't you just use a pure-coilgun instead?
Well, What if you already had regular guns laying about?
Turns out Boeing had the same idea, and filed this patent: https://patents.google.com/patent/US10041757B2/en
The patent assumes you already have a stockpile of guns around. You've already bought the guns, and modifying them to accept more powerful projectiles would mean having to make all new guns so you don't have a way of making them more powerful through chemical means. So instead of buying all new guns, you put this coil-gun barrel extension on the end of the barrel. You can then plug into whatever nearby power source you have and supercharge the round on its way out. The patent also lists some additional benefits for being able to precisely control the speed of the projectile to make artillery more accurate.
TLDR
There might be a niche use for Hybrid Chemical / Electrical guns for militaries that have older conventional guns laying around that they want to upgrade on the cheap.
Sure, you could build a conventional chemically powered gun with black powder and everything, and then further accelerate the bullet with a coilgun at the end... but my initial thought was that this would be needless complex. Would there be any advantages to using both types of propellant to contribute 50% of the firepower over just making a weapon that gets all its firepower from one type?
To answer this, I went to check out if such a thing already exists IRL. If it does, then someone probably built it because there is some use for it.
BUT, no such weapon seems to exist.
I did find this patent though: https://patents.google.com/patent/US20160341514A1/en
This patent is for a chemically powered gun, that vents some of the gas into a second tube to power a second gun. The second gun's bullet passes through coils which slows the second bullet, and provides some extra thrust to the first bullet through a coil-gun assembly at the end of the first gun. This seems massively inefficient and complicated. Certainly as shown in the patent, it would be better to just make a gun that can accept a larger bullet and use all of that propellant for the bullet instead of losing a lot of your power by all the conversion steps that need to happen.
Trying to think of applications, perhaps you could use this idea to get more distance out of a single ammo type. For example if all you have is one type of bullet, you could load two into your gun and use one bullet's energy to power a coil-gun to further accelerate the other bullet. You could also scale that up to use 10 bullets to power one bullet. This could turn a stockpile of regular rifle ammo into more of an armor-piercing projectile... BUT This is a lot of added complexity and a very heavy system when compared to "Just using a gun with a bigger bullet".
My second thought was "Maybe there is some use in using a coil gun at the end of a regular gun to help precisely control the speed at which the bullet leaves?" Of course that doesn't make much since because why wouldn't you just use a pure-coilgun instead?
Well, What if you already had regular guns laying about?
Turns out Boeing had the same idea, and filed this patent: https://patents.google.com/patent/US10041757B2/en
The patent assumes you already have a stockpile of guns around. You've already bought the guns, and modifying them to accept more powerful projectiles would mean having to make all new guns so you don't have a way of making them more powerful through chemical means. So instead of buying all new guns, you put this coil-gun barrel extension on the end of the barrel. You can then plug into whatever nearby power source you have and supercharge the round on its way out. The patent also lists some additional benefits for being able to precisely control the speed of the projectile to make artillery more accurate.
TLDR
There might be a niche use for Hybrid Chemical / Electrical guns for militaries that have older conventional guns laying around that they want to upgrade on the cheap.