Just a heads up, you may not be basking in the glory of OTC suppressors as quickly as you think. Even if the HPA passes, you've still got the issue of CO law to deal with. In which Federal Registration (tax stamp) is affirmative defense, ie. Suppressors aren't just perfectly legal in CO, and many other states. Without the Federal Registration on them, the laws in CO needs to change before you can take advantage of the HPA's provisions.
(1) As used in this section, the term “dangerous weapon” means a firearm silencer, machine gun, short shotgun, short rifle, or ballistic knife.

(2) As used in this section, the term “illegal weapon” means a blackjack, gas gun, metallic knuckles, gravity knife, or switchblade knife.

(3) A person who knowingly possesses a dangerous weapon commits a class 5 felony.  Each subsequent violation of this subsection (3) by the same person shall be a class 4 felony.

(4) A person who knowingly possesses an illegal weapon commits a class 1 misdemeanor.

(5) It shall be an affirmative defense to the charge of possessing a dangerous weapon, or to the charge of possessing an illegal weapon, that the person so accused was a peace officer or member of the armed forces of the United States or Colorado National Guard acting in the lawful discharge of his duties, or that said person has a valid permit and license for possession of such weapon.

- See more at: http://codes.findlaw.com/co/title-18....1NrcA6M8.dpuf