>From another list:

>> I'd feel safer screening a [rocket] motor with bulletproof glass. What 
>> does the
>> sandwiched layer (acts a glue) consist of again_ transparent silicone 
>> resin?
>> Probably something better.

> The internal layer in bulletproof glass is Lexan or its equivalent.  The 
> stuff we use is 1.3" thick, so glass would be superfluous.  I've heard, 
> but not confirmed, that this will take three .50-cal rounds in the same 
> spot without failing.  It will certainly take anything we can throw at it.

    I'm not sure about the material you are using but in the past we had 
lots of 1" thick pieces of
lexan from surplus.  We wanted to find out how bulletproof it really was so 
we got a couple of guns
and about a dozen sheets of the stuff and went shooting.

The 357 mag with hollowpoints was stopped in one 1" sheet with very near 
penetration and some
distortion on the far side.
38 stopped way sooner, so did the 45.  Didn't have a 44 mag.

As for rifles, the jacketed lead 30-06 penetrated a couple of sheets to 
about 2.5"

A 7.62mmX39 steel core round penetrated 5" of lexan.

And in the most telling, the 308 NATO steel core jacketted round penetrated 
6" of lexan leaving the
copper jacket in the first 1" sheet.

So bulletproof glass is NOT bulletproof except from lead core handgun rounds 
until you get VERY
thick or use a sandwitch construction like glass laminated onto thick lexan. 
You need to mushroom
the projectile to get it to stop in lexan, if it is poointy and fast it will 
penetrate.

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