What I did this weekend

[whyitell]

.4 I thought you guys used .2, .4 bbs must really hurt.

[Jahona]

The physics behind airsoft can really make your head spin.  It's not as easy as fps and weight.

[Jaysers]

For example. I still don't understand the term: making the bullet "hop" or "jump" by switching some lever on a shotgun.

[Jahona]

That's the hop up unit.  Basically theres a cylinder of rubber that goes around the back part of the barrel.  When you move that lever, wheel, or slider, it moves a bar on top that pushes a small soft nub that in turns pushes the rubber down into the barrel.  When the bb hits this it creates backspin.

Here is a good article that explains how this voodoo magic works: http://www.airsoftforum.com/board/Hop-Works-t73843.html

[whyitell]

What gun/guns do you currently own, and I thought that you needed to have 50% of you gun a special colour, maybe that's just the uk.

[Jahona]

US laws all change between state and city policies.  The orange tip is required to be on when guns are imported into the country.  Some states require the orange tip to be left on some dont.  Most of the time private property trumps regulations.  I never ever suggest playing airsoft in public parks.

As for what I own. 
Custom G&P M4 with Daniel Defence MK18 rail.  R-hoped Prometheus barrel.
Echo 1 MP5a4.  Mainly stock with some minor performance mods.
Echo 1 G36c.  Has a short in it that I haven't gotten around to fixing.
KWA USP .45

[thealex447]

Doesn't the BB slow down more from air resistance with increased hop up? Most of my knowledge with backspin comes from golf, and less spin usually means more distance.