Well, I believe someone made a needle rifle and I gave some numbers there. Assume the smallest crystal he's firing is able to kill a man, or at least kill them 50% of the time and the rest of the time make them very close to dead. Electricity is weird. It has an odd habit of not killing people when it should and killing them when it shouldn't. Hm.
Gauss rifle, normal shot...eh...Not grapefruit fat, but a bit unwieldy, like 8 inches long or so, but thin.
Assuming that 'eight inch but thin' shard that he said contains 2 TPU uses the same dimensions as a PSL shard, which is the default shape it forms when in a uniform tube, it's an inch wide. Which means it would form a sphere with a radius of ~1.25 inches, and of course would use a much smaller volume of fluid.
But what's interesting is that it's exactly 64 times the volume of a single Testament shard. Which means a standard magazine, which (I think) is about the size of a drum magazine, holds 27 potential TPU. Compare to the laser rifle battery, which holds 120 TPU in a smaller battery, this isn't size efficient.
Since that magazine holds a thirtieth of a full PSL mag, that means a single full-size PSL shard has
twenty seven TPU coursing through it- equivalent to firing a tesla arc for 2.7 seconds. And here I thought most of the damage came from the explosion.
Further, you get those shards at a rate of 7.5 per token. That's potentially 202 TPU worth of fuel, for a single token. Compare to the cutting laser, which has our best token:TPU ratio (1 token per 240 TPU), that's... well, it's not particularly bad, but we have better.
So, in closure, PSL fluid functions as a way better power source than I thought it would. But it isn't more size or power efficient than what we already have, under ideal situations where you get all the energy out of it. It's not a good choice for a power source, especially when you consider that it's an armor piercing frag grenade.
Oh, and that revised FEL's proportions are weird. I was basing the stock's length on how large the trigger hole was, but the grip you added is about as long as the trigger hole itself. If the grip is the proper size, and the trigger hole is just absurdly massive, then the stock's original size was good.
This spoiler originally ended by complimenting Sean greatly, due to my original calculations having an error somehow resulting in a token:TPU ratio of 1:~1600. I wish that hadn't been a mistake. ._.