Quote:
Originally Posted by malloyd
The magnets on the other hand.... The barrel on this thing is essentially just a guide rail right? Plays no part in the actual energy transfer, so no, it doesn't get any hotter than, say, the stock of a chemical slugthrower. The parts that are involved in the energy transfer have to be somewhere though.
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Certainly. The GR-1 Anvil stores approximately 3.2kJ of energy, and has an efficiency of 2.8%. So approximately 89-100J ends up dumped into the projectile, leaving approximately 3kJ to become waste heat. That's, not an inconsequential amount, in fact, it's roughly comparable to the energy contained in 1 gram of gunpowder.
1 gram of gunpowder is about 15 grains, which means a .22 short is propelled by about 700ish Joules. Given the high mass of the GR-1, it's not surprising that it doesn't heat up terribly fast, but it also doesn't eject hot brass; and the brass of the ejected cartridge in a conventional firearm carries a great deal of the heat away, and the GR-1 lacks this means of shedding waste heat.
A ruger 10/22 has to absorb about 900J of waste heat in a 2.25kg platform. The GR-1 is absorbing 3100J of waste hit in a 10kg platform. So we're looking at something like 400J/kg of heat for a .22 and 310J/kg of heat for the GR-1, which places it in a comparable range in terms of overheating. These are "meatball math" numbers because there's things to deal with like the aforementioned hot brass being ejected can carrying substantial amount of heat away.