Firearms are one kind of machines with interesting aspects to think about. I've thought a lot about gas expansion, aerodynamics, vibration, heat conduction and other phenomena by thinking through them. Don't own one, won't get one. I'm not interested of them that way
Well the experimental technologies are interesting as well. Railgun design is being made challenging by rail corrosion concerns. Coilguns have little hope in being very effective due to magnetic saturation issues. Gauss guns have the physical strength of the magnets as the restricting factor, so not much improvement can be had there. Particle accelerator type weapons are too far to even think about. Plasma guns can't confine the plasma to a reasonably focused, long jet. Laser type guns have horrible power output/weight ratio, among other concerns. But, it's all interesting..
Then, there's some old mechanical designs.. but springs give horrible stored energy/weight ratio, not to mention low projectile velocities. Compressed gas systems suffer from the same.
It's no wonder the best method to propel the projectile has stayed much the same - it's just so good.
I thought I invented a major improvement by replacing the chemical low explosive propellant with a fuel-air combo, something which would save space in propellant storage. But then, someone had figured that out before me.. the projectile speed would be severely restricted by the speed of the flamefront propagation
The weird thing is that I don't want any more weapons in the world, yet I've spent such time thinking about improvements to them, just 'cos it's posing an interesting engineering challenge
Well, done the same thought exercises for imagining improved medical imaging equipment, and countless other systems
Hey, I'm still waiting to find out what gun is the perfect match for a male INFJ. This is crucial information in case I ever want to own one. It's your duty as a gun fanatic to inform of such.
I tell you what...since that is such a good question....I will actually research it by thinking of the traits of INFJs and matching them to types of firearms. I'll have you the answer by the end of the week. That way I can be sure that my research was thorough. You want a handgun, right?