Re: E-mag weapons builder
 

This over here written by a poster here who I believe is a physicist might be helpful!

Re: E-mag weapons builder
 

Email me at gamingballisticllc at gmail dot com and I’ll ensure you get the latest version (2013)

Re: E-mag weapons builder
 

What are you talking about, it clearly says "projectile's mass," and has always been that way. We've always been at war with Eastasia. Please disregard the part that says it's been edited in the last few minutes, that was just for some spelling errors.

Yeah, spelling errors. That's my story and I'm sticking to it.

No idea; could be taken from the firearm design system from 3e (which you can find in GURPS Classic: Vehicles), extrapolated from the weights in UT, or from somewhere else; we'll just need to wait for him.

Re: E-mag weapons builder
 

Looks like Douglas beat me about the sheet and kinda, his numbers do shorta break down at the extremes but that's because once you get to needing to cover for hyper velocity shock waves the math gets super complicated and requires you to know a lot of factors behind the projectiles material properties and shape and is math far beyond using a pen and paper and would require complex computer modeling. Unfortunately there is no easy way to handle it.

As for my 900 yards figure this is more of a estimation based on how GURPS handles ranges rather then hardcore physics and is not based on the spreadsheet either.

And derp, that's supposed to be 3 kilojoules not kilograms lol. I wrote that on my smartphone and I guess it got autocorrected. 3kJ is roughly the muzzle energy of the rifle, TL10 EM weapons are 50% efficient. Ultra-tech TL10 power cell holds 720kJ/pound.

Also someone asked about a weight factor, I'm assuming they mean the 7.1lbs? That's just the weight of an unloaded 4mm gauss rifle, the heavy automatic figure came from reverse energering the weights of weapons that had both normal and machine gun versions. The square weight of KE is just how the gun design system seems to handle it (at lest at the time I Iearned that, David Pulver has since changed some elements of how EM weapons are designed but I don't, sadly, have the actual numbers).

Re: E-mag weapons builder
 

I've looked at the rules for building electromagnetic guns from 3e, and they seem like they'd work okayish for 4e. The biggest issue AFAICT is that for really big guns the weight seem implausibly low, because the empty weight of guns is based on the square of caliber rather than the cube or something like that.

Re: E-mag weapons builder
 

This is a problem with conventionally large caliber guns as well in the system. Using the cube of of caliber gives betterish results and is what Spaceships uses (though... guns in that system has it own issues). The rules for the weapons design system that will be in the VDS uses a scaling factor to account for this though sadly I don't know what the number is....sadly it might be years still before it sees the light of day =_=