4 ms·

86 Joules at the muzzle: in context, about half the energy of a 40 grain .22LR.

by hprotagonist 5y ago

graderjs 5y ago
However the Joules are tunable. You can dial up and down, I believe.
- GravitasFailure 5y ago
  To a point. Once the magnetic field gets to a certain strength, the projectile magnetically saturates and the only way to really get more kinetic energy into it is to make the barrel longer. If they can demonstrate this firing the equivalent to a .22LR, it would be really amazing. Edit: They claim "up to" 75 ft-lbs muzzle energy, which is in the realm of .22LR. Check out this chart: https://www.mcarbo.com/22LR-Ballistics-Chart https://www.mcarbo.com/22LR-Ballistics-Chart
  - graderjs 5y ago
    Awesome, this is why I come to HN, for comments like this; to learn. (aside from the dopamine hits from posting...)
  - amluto 5y ago
    Doesn’t saturation of the projectile mean that further increases in field strength increase acceleration roughly linearly instead of quadratically?
    - GravitasFailure 5y ago
      Yes, but it also means an already inefficient system takes an absolute nosedive in efficiency.
motohagiography 5y ago
Non-firearms guy reading, was just looking at muzzle velocity, ~245fps (75m/s), where a .45ACP round goes ~500fps. - but joules would be the way to compare the physics. In terms of energy/silence, for hunting, it seems like you can buy more powerful crossbows at a camping store. Additional energy just seems like an optimization problem that could be solved with an external power pack source. However, the real game changer may be in the economics of EMP shielding and weapons, where if all legal civilian firearms are electronic, they are also remotely manageable via DRM and less user servicable. The analogy could be like what electronic fuel injection did to carbeurators and the autonomy of drivers to service their own vehicles. This rifle seems like a bit of a gimmick, but from a political perspective I could see some people saying, "let them hunt with coilguns, nobody needs gunpowder anymore," which will be a new leverage point on 2A limitations whereby this product is a managed substitute. Independent of where one stands on that issue, the product is a technology that could change the dynamic of that discussion.
- graderjs 5y ago
  interesting diverse take, particularly about EMP, DRM and R2R. i appreciate the political/2nd-order effects perspective!
- nradov 5y ago
  I don't know where you're getting those numbers but nominal .45ACP muzzle velocity is more like 800fps.
  - jakearmitage 5y ago
    Correct. Depends on ammo, though: https://www.federalpremium.com/handgun/premium-personal-defense/personal-defense-hst/11-P45HST2S.html https://www.federalpremium.com/handgun/premium-personal-defe... https://www.scribd.com/document/342603372/45-ACP-Ammunition-Velocity-Results-in-FPS-by-Gun#from_embed https://www.scribd.com/document/342603372/45-ACP-Ammunition-... So he could have sourced that info from a subsonic load out of a short barrel? But even then, it would be in 600 zone.
    - GravitasFailure 5y ago
      Subsonic is anything under 1125fps, with some variance for local weather conditions, and .45 ACP is popular to use with a silencer because standard loads are almost always subsonic. 500fps seems consistent with the absolute low end of some target loads.
beloch 5y ago
More context: "The GR-1 is capable of accepting 3 different standard projectile lengths (32 mm, 42 mm, and 52 mm) with a unique variable magazine system" "Muzzle Velocity: 75 m/s." 75 m/s is slower than a lot of bows, and those are fairly big slugs, as compared to a .22 bullet. What you should expect with this gun is a very curved trajectory and, likely, low accuracy. At the very least, it will need sights similar to what's available for bows, since a few meters of distance in range will have a large impact on where the bullet lands. The large size of these bullets means they might actually not penetrate much, if at all. (I'd appreciate more spec's than just their length). Yes, they have half the kinetic energy of a .22 round, but that's going to be spread over a much larger impact area.
- moftz 5y ago
  You could easily put a point on the slug and give it some penetrating ability. It might not blow a hole through you but could at least break a bone or puncture some blood vessels.
rasz 5y ago
Another comparison: the ballsiest Airsoft limit I know is set by Poland to 17 Joules, with something like Frances 2J at the other end of the spectrum.

86 Joules at the muzzle: in context, about half the energy of a 40 grain .22LR.

graderjs 5y ago

However the Joules are tunable. You can dial up and down, I believe.

GravitasFailure 5y ago
To a point. Once the magnetic field gets to a certain strength, the projectile magnetically saturates and the only way to really get more kinetic energy into it is to make the barrel longer. If they can demonstrate this firing the equivalent to a .22LR, it would be really amazing. Edit: They claim "up to" 75 ft-lbs muzzle energy, which is in the realm of .22LR. Check out this chart: https://www.mcarbo.com/22LR-Ballistics-Chart https://www.mcarbo.com/22LR-Ballistics-Chart
- graderjs 5y ago
  Awesome, this is why I come to HN, for comments like this; to learn. (aside from the dopamine hits from posting...)
- amluto 5y ago
  Doesn’t saturation of the projectile mean that further increases in field strength increase acceleration roughly linearly instead of quadratically?
  - GravitasFailure 5y ago
    Yes, but it also means an already inefficient system takes an absolute nosedive in efficiency.

motohagiography 5y ago

Non-firearms guy reading, was just looking at muzzle velocity, ~245fps (75m/s), where a .45ACP round goes ~500fps. - but joules would be the way to compare the physics. In terms of energy/silence, for hunting, it seems like you can buy more powerful crossbows at a camping store. Additional energy just seems like an optimization problem that could be solved with an external power pack source. However, the real game changer may be in the economics of EMP shielding and weapons, where if all legal civilian firearms are electronic, they are also remotely manageable via DRM and less user servicable. The analogy could be like what electronic fuel injection did to carbeurators and the autonomy of drivers to service their own vehicles. This rifle seems like a bit of a gimmick, but from a political perspective I could see some people saying, "let them hunt with coilguns, nobody needs gunpowder anymore," which will be a new leverage point on 2A limitations whereby this product is a managed substitute. Independent of where one stands on that issue, the product is a technology that could change the dynamic of that discussion.

graderjs 5y ago
interesting diverse take, particularly about EMP, DRM and R2R. i appreciate the political/2nd-order effects perspective!
nradov 5y ago
I don't know where you're getting those numbers but nominal .45ACP muzzle velocity is more like 800fps.
- jakearmitage 5y ago
  Correct. Depends on ammo, though: https://www.federalpremium.com/handgun/premium-personal-defense/personal-defense-hst/11-P45HST2S.html https://www.federalpremium.com/handgun/premium-personal-defe... https://www.scribd.com/document/342603372/45-ACP-Ammunition-Velocity-Results-in-FPS-by-Gun#from_embed https://www.scribd.com/document/342603372/45-ACP-Ammunition-... So he could have sourced that info from a subsonic load out of a short barrel? But even then, it would be in 600 zone.
  - GravitasFailure 5y ago
    Subsonic is anything under 1125fps, with some variance for local weather conditions, and .45 ACP is popular to use with a silencer because standard loads are almost always subsonic. 500fps seems consistent with the absolute low end of some target loads.

beloch 5y ago

More context: "The GR-1 is capable of accepting 3 different standard projectile lengths (32 mm, 42 mm, and 52 mm) with a unique variable magazine system" "Muzzle Velocity: 75 m/s." 75 m/s is slower than a lot of bows, and those are fairly big slugs, as compared to a .22 bullet. What you should expect with this gun is a very curved trajectory and, likely, low accuracy. At the very least, it will need sights similar to what's available for bows, since a few meters of distance in range will have a large impact on where the bullet lands. The large size of these bullets means they might actually not penetrate much, if at all. (I'd appreciate more spec's than just their length). Yes, they have half the kinetic energy of a .22 round, but that's going to be spread over a much larger impact area.

moftz 5y ago
You could easily put a point on the slug and give it some penetrating ability. It might not blow a hole through you but could at least break a bone or puncture some blood vessels.

rasz 5y ago

Another comparison: the ballsiest Airsoft limit I know is set by Poland to 17 Joules, with something like Frances 2J at the other end of the spectrum.