Honestly I never saw the point of arming time.
When it came to the Lumberjack, it made sense...I was a huge fan of the Lumberjack before the arming time, and basically, you had a Carronade that could shoot across the map...or at point blank range...which...well, really replaced the Carronade.
Now, when it came to Heavy Flak, it kinda made sense...
But the problem now, the Flak still supposedly has its arming AoE, which does a meager 50 Explosive, the Direct does 115.
With a regular round, those four shots will do 644 perma hull damage
Buff vanilla would do 837 damage.
That's without the 50 AoE explosive
The AoE would add 280 perma hull a clip, which, yes, would be great...as that does a total of 852.
So
That will kill, with no problem: Pyramidion and Junker
If we put in account of Burst rounds, that's 805 Damage, which is just about an Armed Vanilla time. The Pyramidion and Junker are instantly doomed at point blank range of 1 Heavy Flak
Buffed Burst: 1046
That kills everything BUT the Galleon and Goldfish.
Lochnagar
523.25 permahull damage
Buffed: 680
(granted you'll get the AoE Damage, which adds 162 damage...for a grand wopping 685! WOOO. YOUR GUN IS BETTER WITH BURST)
Yeah you're not gonna Loch this gun
Charged
579 permahull
752 buffed
Greased
644
837
Just a solo, it seems that the obvious choice is the use burst rounds since it will do the most damage at any range because you don't have to wait for the AoE.
Double the damage when you have two Flacks on a Galleon.
In fact, the Double Flak Galleon was the reason why the call for an Arming Time happened after Lumberjack did, if you remember correctly.