I've tested many materials and different pellet types... for Airsoft use.
I can tell you this much though:
1 layer if Fiberglass isn't enough. 2 withstood a 400 fps rifle with 0.3gram pellets... but it left a dent.
Also with "lightweight" thin armor types if you move in a weird way or even flex the surfaces can break, bend, deform, etc. I tried out a whole leg section consisting is ODST thighs, shins, knees, and sandals... and the back of the shin piece broke when I crouched a section of the front caved in and shattered... putting splinters in my skin.
After that I tried 3 layers of fiberglass and 4 layers of Rondo. This withstood my rifle up to 0.45 gram pellets... but was iffy when it came to mobility... not to mention it started to get heavy on me.
Some key things to remember...
- If your armor is too thin it will crack when you do anything other than walk.
- If your armor is too thick it will become heavy and too stiff to flex when you need to get into awkward shooting positions and prone.
- If your armor is too thin it WILL NOT withstand even a small plastic white ball coming out of an Airsoft gun. Bummer.
- If your armor is too thick... well actually ballistics wise it should stand. If you use fiberglass it can warp... however.
What you want is armor that is thick enough for you to at least run in and not be too heavy. Also consider breath-ability. You don't want a solid ODST helmet with no vents... like what I did. It fogs up your visor and makes you really really hot.
Thing is, Halo armor isn't... realistic. At least in Halo 4 the possibilities are greater than say Halo 3, but Bungie/343's image of metallic super-suit that can withstand a drop from space doesn't go well with on-ground action we face today.
- First of all, you can't shoulder your rifle with bulky shoulder pieces and shiny breast pieces. Just look at yourself in Halo 4. Your character shoulders their gun WITH THEIR SHOULDER. Bye bye Chris Costa, everything you taught me is invalid.
- Also, obstructive helmets... You know those huge hazop breathers on the front of your helmet? Yeah they block your sights. I needed three risers moving my Eotech up 2 1/2 inches for me to see. It's ugly and impractical.
I'm currently building a Dead Space 2 Earthgov Security Suit. Take a look at it's armor design. It doesn't have huge obstructive panels all over, and flexible materials where lots of action happens. Now I have to figure out how I need to feel or hear my hits. I don't want to be a cheater not calling my hits after all.
So. What is there to be learned here? Well... ODST is possible. I've done it before. It didn't last though, because unlike my skin which can regenerate when hurt the suit is brittle and worst of all uncomfortable. I went back to my FAST Helmet and Plate Carrier after two days of gaming.
What I'm trying to say is... it's difficult. You need flexibility if you are being shot at or shooting back. Visibility can be a problem for some helmets as well I just noticed, for example the soldier helmet. It has a super skinny visor. I may be Japanese but that's taking it too far lol. For every suit functionality is different and takes a lot of work to get it to work. just getting a hard enough visor took me a week to do, not including the mounting nightmare.
It's possible, get creative.
I should make a full fledged report on it's own thread shouldn't I...