Low Tech cannons mortars and shells

[Rupert]

Originally Posted by Varyon

I've seen this figure mentioned before, but can never remember it when these threads pop up. Is it actually stated somewhere in the GURPS books, or is it just something that has been extrapolated from existing weapons? Also, what impact should various means of increasing fragmentation (shell walls specifically designed to fragment, having premade fragments inside of the shell, etc) have on this?

I don't recall if any author actually stated it. However, all of HT's and UT's warheads, shells, etc. follow this rule, allowing for rounding, except some of HT's hand grenades.

Well, following the rapid fire table, doubling the number of fragments should give +1 to hit, and would reduce each fragment's damage to 70% of the original. Four times as many would be +2 to hit and x0.5 times the damage. Basically the same as adjusting the number of pellets in a shotgun shell, just don't worry about the exact numbers, just the ratios.

In my view every doubling of shell diameter should also probably give a +1 to hit, probably using 40mm as a baseline so 40mm+ gets +0, 80mm+ a +1, and so on. Going down I'd be generous and say 20mm and under gets -1 and 10mm and under gets a -2.

I think there were low tech attempts to increase fragmentation by including nails or other preformed fragments inside of the grenades, like the Chinese land mine on LT86 (that used lead balls... which somehow do crushing damage instead of the piercing damage of most high-velocity lead balls in GURPS).

Maybe they're considered to be fairly slow, like sling bullets? Otherwise, I have no idea. The 14d explosion is going to be far more of a worry for most characters anyway - the 'fragments' are really just icing.

...and maybe make them pi instead of cut, probably with a poor armor divisor (ideally, the armor divisor would go down with fragmentation damage, to represent larger fragments having more difficulty getting through DR but causing more severe wounds when they do - the latter is already handled by using 2/3 power - but that might be a bit too difficult to implement in practice).

Cutting actually describes fragments pretty well - compared to injury they penetrate poorly (though perhaps not as poorly as they should), and they tend to be irregular and jagged shapes that cut and tear.