For gun colectors I have read a number of things of corporate gun ownership and loopholes:
"In some areas it is difficult to get a law enforcement signature on the ATF Form 4. To circumvent this problem, some people purchase the gun through a corporation. If you are a SOT payer acquiring a firearm from a private source, or if you are a private individual who is incorporated or is a senior officer in a corporation, you can acquire an NFA firearm on an ATF Form 4 without the need for a law enforcement endorsement, photograph, or fingerprint card. You still must pay the Federal Transfer Tax. If the gun is transferred to a corporation, it must be retained by the corporation until it is dissolved. At such time the gun must be sold on a tax paid transfer, retitled to someone on a tax paid transfer, or surrendered to the BATF." http://www.funsupply.com/Firearms/corp.html
Of corse state laws still apply.