Hop...

[EDcase]

back when i started airsoft  (2001 was my first gun) everything was .20g and maybe .25g

what changed?

Heavier BBs are less affected by wind/leaves etc (higher inertia) so fly further/straighter depending on overall power and hop.

Lower weight BBs fly faster so if your pew manages to fling them far enough there may not be much point going heavier.

 

[ButcherBill]

what changed?

EVERYTHING.

 

[Adolf Hamster]

Lower weight BBs fly faster so if your pew manages to fling them far enough there may not be much point going heavier.

i'd argue the lions share of perceived longer flight time is due to the heavier bb's travelling further, ie past a short distance the heavier round can actually be faster at getting from a to b until it's the case that the lighter round can't even make it to b.

although in the case when the bucking can't spool up the heavies without robbing enough energy to negate the range benefits your point does apply.

however if the circumstances mean you're not using the extra range then no point spending extra for a benefit you're not using.

back when i started airsoft  (2001 was my first gun) everything was .20g and maybe .25g

what changed?

heavier rounds became more available/cheaper, off the shelf buckings made it easier to spin them up, and enough people started using them to notice the benefits.

 

[mirinjawbro]

seems an easyish thing to not notice back then. 

despite all that i miss the days of Marui, KWA/ KSC, WA and ICS.

 

[Lyndication]

Lighter BBs fly faster right out the barrel, but given that all BBs are the same size and surface finish, they suffer the same amount of drag.

The lighter BBs suffer more air resistance though, because they go faster. So they slow down much sooner and lose a lot more of their energy.

 

[EDcase]

...despite all that i miss the days of Marui, KWA/ KSC, WA and ICS.

Why, they're still around.  (The one I miss is Classic Army)

But there are many others now and overall quality has gone up with prices going down.

 

[Lyndication]

WA has gone the way of the dodo mostly, but the system has been improved upon by like three different companies now.