Explosive Bullets

[SuedodeuS]

Alternative Title: Fun ways to violate the Hague Convention.

The purpose of this thread is to make plausible guidelines for explosive bullets of various sizes, with an emphasis on small arms. High-Tech does give some general ideas of how much explosive (by bullet weight) is in each type of explosive round, which is where we'll start.

LE: HT gives a lower bound of 15%, but gives no upper bound. What should be the highest it could go? 50%? 60%? Higher still? What would be the amount of gunpowder found in a "typical" LE round? In addition, should some of the lower TL explosive rounds have a chance to fail to go off (just like SAPLE)?

SAPLE: With an upper bound of 10%, there isn't a lot to play around with. The only real question is what the typical SAPLE round would have.

APEX: Fairly straightforward, with a small range possible (upper bound 5%). The big question here (and with all HE rounds) is which high explosive is generally used at each TL? Of course, the %age of HE used in a typical APEX wouldn't be too bad to know either.

HE: HT makes reference to the LE entry. Does this mean the rounds are basically "LE, but with better explosives?" As always, the typical explosives (and amounts) used would be nice to know.

SAPHE: As with HE, this seems to be "SAPLE, but with better explosives."

SAPHEC: HT notes that these rounds tend to have around 20% weight dedicated to payload. In this case, a typical range would be nice.

APHEX: Is this basically APEX, without the decrease to basic damage? No range or average for % explosive is given.

Larger rounds: All the explosive rounds listed beyond this point have minimum calibers of at least 20mm, meaning small arms are pretty much out. However, in a recent thread, it was mentioned that there was (at least at some point) a HEAT round for a shotgun (!!!). What rounds might legitimately be able to scale down to a size usable by small arms, and would the stats end up being different in some way (notably the CPS multiplier and TL)? As always, some ideas of mass devoted to payload, explosives used, etc would be nice.

CPS: When making such rounds, should we multiply the CPS as noted and then include the cost of the explosive, or is explosive cost considered to be subsumed in the multiplier?

Damage: Determining damage for SAPHEC rounds (once you know amount and type of explosive) is easy enough - use the equation from B415. However, one would expect that, in a fragmentation explosion (which occurs in all the other cases, ignoring the larger rounds), some of the force is "wasted" creating (and throwing) fragments. Are there any good guidelines on how to make this work? Something like sacrificing 1d cr ex for [2d] is what I'm looking for here (although not necessarily those numbers).
The larger-caliber rounds make use of a different mechanism than simply "blowing up," meaning that they should probably modify the B415 rules in some manner. In the case of something like HEAT, it might be as "simple" as sacrificing some portion of the explosive damage for an increased armor divisor. Any ideas on how building these rounds should function?


These are issues that I think would be beneficial to resolve, particularly for creating new rounds (rather than using existing ones, trying to dig up their real-world statistics, and then converting these to GURPS). Unfortunately, my experience with explosives is limited to Independance Day celebrations and reading stuff online, and my experience with firearms is even less. Basically, I'm asking if anyone has already worked out some of these issues... or if they'd be willing to help me work them out!

As a final note, I understand perfectly well why these stats weren't included in High-Tech. They are likely too highly variable to be given more "screentime" than they were, as it would have likely been impossible to give them a thorough, proper treatment and still stay within page limits!