Where can I find all the rules and regs for modifying an AR 15?  I don't want "Big Brother" knocking on my door with one of those shit eatin grins as my beloved weapon is taken and I end up in prison.

What kind of modifications are you talking about?  Barrel length?  Pre-ban questions?

Pre-bans: mags, barrel, stocks, sound/flash suppressors, select fire, the works.

I would start with James Bardwell's FAQ on National Firearms Act Weapons.

Try this URL:

http://www.cs.cmu.edu/afs/cs.cmu.edu/user/wbardwel/public/nfalist/index.html

Check the FAQs under nfa_faq.txt.

It looks like in IA:

Machine guns are out except for Law Enforcement and dealers.

Sound supressors, short barreled rifles, short shotguns, large bore destructive devices, and explosive, incendiary, or poison gas destructive devices are limited to items designated as collector's items by the Commisioner of Public Safety (basically Curio and Relic list).

That leaves AOW's.

I would also check out the M16-Full Auto forum for more information.