Obscure ammunitions?

[imagine_74714]

Why are some manufacturers chooses to chamber their firearms with ammunition that are radically different than what others are using? Are they hoping it would catch on and become more popular choice, or is there other reason that I don't see? Whenever I see P90, or that new SMG from Knights Armament, I just wonder. They are large company with years of experience, and they can't be just gambling with their productions like that. Anyone care to elaborate?

P.S. Are all the pistol-round SMG became obsolete in today's war? I don't see them as much as I've seen them back in 90's, especially, HKs.

 

[HeVGunner]

Generally these companies create new rounds because nothing existing or in common use meets the needs of whatever they are trying to accomplish- in the case of the p90 they wanted the ability to pierce body armor to fairly extended distance in a short light package. Generally this couldn't be accomplished with the pistol cal rounds currently available.

I imagie KAC's new 6x35 is a similar attempt to achieve greater potential lethality than pistol cal carbines by using a kind of "carbine" intrmediate round that is more powerful than a pistol round, but not quite a rifle round.