If the speed of light were infinite, what would the equation of special theory of relatively reduce to!

There is no such thing as "the equation of special relativity" hence there is nothing we can reduce.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.