弹药：
X:Factoriodatabaseprototypesitem
查找如下字符串
name = "railgun-dart",
找到如下段落
{
type = "ammo",
name = "railgun-dart",
icon = "__base__/graphics/icons/railgun-ammo.png",
flags = {"goes-to-main-inventory"},
ammo_type =
{
category = "railgun",
target_type = "direction",
action =
{
type = "line",(弹药效果类型
range = 25,(距离，附图中距离为128
width = 0.5,(宽度，为伤害实际宽度，不是效果宽度，附图中距离为32
source_effects =
{
type = "create-entity",
entity_name = "railgun-beam"(弹药实体
},
action_delivery =
{
type = "instant",(造成伤害的方式
target_effects =
{
type = "damage",
damage = { amount = 100, type="physical"}(伤害数值与类型
}
}
}
},
magazine_size = 5,(每发弹夹弹药数量
subgroup = "ammo",
order = "c[railgun]",
stack_size = 200(堆叠数量
}
