I imagine that the momentum would be conserved. So if the rifle normally shot a 30 gram ball at 300 meters per second, it would shoot a 5 kilogram ball at around 23 meters per second.
The larger size and lower speed of the cannon ball would likely reduce the range.
The larger size of the projectile would spread out the impact causing reduced damage.
The ballistics would be significantly different making it far harder to hit with.
This is how I would do it in my game:
Reduce the damage from 1d12 to 1d10
Change piercing type to bludgeoning
Reduce range from 40/120 to something like 20/60
Add knockback of 5 ft to medium targets or 10 for small
The really neat thing would be shooting non standard rounds that wouldn’t be possible from a musket like incendiary or smoke rounds.
I think damage reduction would be even more than that. The damage a projectile does to a target is directly related to its kinetic energy which is calculated as e = ½mv². So when you increase mass but reduce velocity you also reduce the damage by the square of the difference in velocity (I think). As long as the damage just relies on the physics of the projectile and not magic, that is.
I was assuming that the total energy would be maintained (In this case 1350 joules) and thus the damage should be the same if weren’t spread out. It has been 20+ years since I has to do any of that math so I could be wrong about any of that. And since the only paper that was handy happened to be an envelope I guess it was technically back of the envelope math. :)
I imagine that the momentum would be conserved. So if the rifle normally shot a 30 gram ball at 300 meters per second, it would shoot a 5 kilogram ball at around 23 meters per second.
This is how I would do it in my game:
The really neat thing would be shooting non standard rounds that wouldn’t be possible from a musket like incendiary or smoke rounds.
I think damage reduction would be even more than that. The damage a projectile does to a target is directly related to its kinetic energy which is calculated as e = ½mv². So when you increase mass but reduce velocity you also reduce the damage by the square of the difference in velocity (I think). As long as the damage just relies on the physics of the projectile and not magic, that is.
I was assuming that the total energy would be maintained (In this case 1350 joules) and thus the damage should be the same if weren’t spread out. It has been 20+ years since I has to do any of that math so I could be wrong about any of that. And since the only paper that was handy happened to be an envelope I guess it was technically back of the envelope math. :)