subsonic

The air began to shimmer around Frogface’s hands, and fine, slithering tendrils emerged from the brightly colored shell and began to drift down toward Marcy, a cloud of tendrils as fine as a cobweb.
Certain now of my target, I breathed, held it, and squeezed the trigger.
Say what you like about the Belgians. They can make some fine weaponry.
The silenced P-90 barely whispered when the burst of automatic fire erupted from the end of the suppressor. There was no flash, no thunder—just a soft, wheezing sound and the click of the gun’s action cycling. Thanks to the subsonic ammunition, the discharge itself actually made less noise than the rounds striking Frogface’s skull.
There were several wet, loud cracking sounds, and every one of the rounds I’d fired struck home. One round would have been messy enough. When half a dozen of them hit, Frogface’s head quite literally exploded, shattered to pulp and shards of bone by the bullets’ impact, and two-thirds of his skull, from the upper lip on up, simply vanished into green-blooded spray.
There was a flash of angry red light from the seashell. Frogface let out a high-pitched, tinny scream, and the nearheadless body began to topple, thrashing wildly.


Side Jobs, Aftermath, Page 401-402