Nitpicking: The .600 Nitro versus the .700

[Purple Haze]

Yes k is determined experimentally for each type of bullet. There are tables standard things like "FMJ boat-tailed spitzer".

The units are "game weight". How massive a creature you can expect to kill with one shot to the chest.

GURPS generally cares about damage to man sized creatures, so these rounds probably should do the same damage as the difference between them will only show up in the guy behind, the guy behind, the guy you shot.

[Tomsdad]

Originally Posted by Anaraxes

Kinetic energy alone would have the 1/2. But there's that constant 'k' in this formula; I assume it's absorbing that constant, as well as adding whatever other multiplier was deemed necessary. Might as well fold all the constants together.

That's true, so as you say we have energy x momentum x a constant
'

Originally Posted by Anaraxes

I suppose you could also define it to fix the dimensional analysis as well. (Whatever the units for "real world damage" are supposed to be...)

[Tomsdad]

Originally Posted by Purple Haze

Yes k is determined experimentally for each type of bullet. There are tables standard things like "FMJ boat-tailed spitzer".

The units are "game weight". How massive a creature you can expect to kill with one shot to the chest.

GURPS generally cares about damage to man sized creatures, so these rounds probably should do the same damage as the difference between them will only show up in the guy behind, the guy behind, the guy you shot.

Do you have a couple of examples of this to look at?

Sorry are you saying that the constant is determined for each type of bullet? or just sub categories

Also when you say "How massive a creature you can expect to kill with one shot to the chest" how are you defining that? Say for example will a wound that eventually kill via bleeding count? Or does it have to a reasonable expectation of instant death, or something in between. Do you distinguish between different bits of the chest will have different effects even when shot by the same round, etc, etc

(sorry I should wait for an example, really!)

[Purple Haze]

Applied Ballistics For Long-Range Shooting 2nd Edition -- Brian Litz

[Tomsdad]

Originally Posted by Purple Haze

Applied Ballistics For Long-Range Shooting 2nd Edition -- Brian Litz

Cool, cheers.

From the blurb it seems to aimed at external ballistics (long range performance in particular), lots of ballistic coefficients etc, but I assume it has stuff about what happens once bullets hit i.e terminal ballistic as well?

[Purple Haze]

I haven't read it. There was a website that had all the tables and calculators for all the formulae. It disappeared 5-7 years ago and the way back machine did not archive any useful pages.

[Tomsdad]

Originally Posted by Purple Haze

I haven't read it. There was a website that had all the tables and calculators for all the formulae. It disappeared 5-7 years ago and the way back machine did not archive any useful pages.

Ah Ok, sorry I thought that was the source of the calculation you mentioned earlier.

FWIW you can find ballistic coefficient calculators about the place.

Cheers

TD

[Purple Haze]

It is, though not the only one, did not see the point of giving early 90's magazines as references.

Part of the point is that you can not calculate damage until you know how fast and at what orientation the bullet hits the target. So you need ballistic coefficient, sectional density, rate of twist, and such.

The formulae in that book will also give drop rates, clicks of windage, drift in a crosswind, and hang time. So you can figure out if you hit the target and at what range.

[Tallor]

Would the Vehicles method from 3e give accurate answers?

[Fred Brackin]

Originally Posted by Tallor

Would the Vehicles method from 3e give accurate answers?

It wouldn't duplicate the stats for the .600 and .700 when I tried it. Those rounds are in a sort of medium velocity band that isn't very common comparatively and that doesn't work well with its' simplifying assumptions.

The Ve2 system isn't very fine-grained about velocity at all. It handles many common rifles, pistols and even artillery pieces quite well for such a simple system but it has its' limits.

This is more likely a job for Douglas Cole's ballistics spreadsheet.