which cartridge would be best for a new concept handgun
im designing a concept handgun (post pics of it when im finished with the design its action is very similar to the iwi desert eagle action but one variant option would be where the front part of the slide which is stationary (on all models) is internally suppressed but it looks as if its part of the slide im thinking of a number of ammo types so far ive came up with the (5.7x28mm, 4.6x30mm, .38-40 Winchester, .35 Winchester self-loading, .30 carbine, 5.8x21mm, 7.62x25mm,) if any one has knowledge of any of the listed cartridges expect for the 4.6-5.7 rounds as im already knowledgeable please give simple answers as to accuracy, penetration, reliability, over all be a good pistol round