departure, discharge, publish, emit, start from, disclose, counter for gunshots
発 centers on the idea of something emerging or being sent out from a starting point: departing, discharging, emitting, publishing, or disclosing. The counter for gunshots is a natural extension of this outward release.
sale; offering for sale; putting on sale; putting on the market; release (for sale)
announcement; publication; presenting; statement; communique; making known; breaking (news story); expressing (one's opinion); releasing; unveiling
development; cultivation; application
discovery; detection; finding
occurrence; incidence; outbreak; birth (e.g. of civilization)
departure; departing from ...; leaving at (e.g. 8:30)
statement; remark; observation; utterance; speech; proposal
explosion; detonation; blast; blowing up; eruption
development; growth; expansion; extension; flourishing
publication (of a newspaper, magazine, book, etc.); issue
firing (esp. a rocket or missile); launching; shooting; discharge; catapult
generation of electricity; power generation
departure; leaving; setting off
nuclear power plant; nuclear power generation
show (of power, ability, etc.); exhibition; demonstration; display; manifestation
dispatch; despatch; transmission; submission
development; growth
opposition; rebellion; revolt; resistance; backlash; refusal
idea; conception
invention
detection (of a plot, fraud, etc.); discovery; coming to light; being uncovered
putting into operation
pronunciation
indictment; prosecution; complaint
発 is the modern simplified form of 發. The older form combines 癶 (a foot stepping forward) with 弓 (bow) and 殳 (a hand holding a weapon), suggesting the release of an arrow or the start of movement. The modern simplification retains the top 癶 but replaces the lower part with a simpler shape.
The top 癶 looks like two legs stepping out, and the lower part resembles a simplified bow and arrow being released. Picture an arrow departing from the bow, discharging forward and starting its journey.
For ハツ, imagine a heart (ハツ) being sent out as a message: the heart departs and discloses its feelings. Heart -> ハツ.