The M1 Carbine is the standard by which all PDWs are measured.

[JASmith]

While we may have difficulty in putting ourselves in the minds of the M1 carbine designers, there is some logic to assuming that a low velocity (by rifle standards) pistol substitute would have round nosed bullets like the pistols it replaced.

The assumed effective range was close enough that a spire point would not have been judged to add enough to velocity retention to be useful. The the spire point round nose would have been seen as drilling through the target so would have been viewed as equal from a wound ballistics perspective.