The relevant bit(s) would be "It shall be unlawful for any person [...] who is an unlawful user of or addicted to any controlled substance (as defined in section 102 of the Controlled Substances Act (21 U.S.C. 802)) [...] to ship or transport in interstate or foreign commerce, or possess in or affecting commerce, any firearm or ammunition; or to receive any firearm or ammunition which has been shipped or transported in interstate or foreign commerce."

So a prosecutor would need to prove that I was "an unlawful user of or addicted to any controlled substance" at the time that I received a firearm or ammunition that has crossed my state's borders (which would presumably be nearly all the firearms and ammunition I own, but still). There's also the parallel prohibition on the seller's end (and another one involving the actual background check questions), with the same present-tense language of "is an unlawful user of or addicted to any controlled substance".

> If third party hearsay is good enough for a warrant why wouldn't video evidence of you at the gun store and the pot shop?

A warrant != a conviction. The video evidence of me at both stores would not establish that I was "an unlawful user of or addicted to any controlled substance" at the time that I took possession of the firearm.

Now, if there was video evidence of me smoking a phat blunt right outside the gun store before walking in and walking back out with a firearm, then yeah, that'd be a slam dunk case (assuming the prosecutor could convince a jury that it was indeed cannabis I was smoking). Likewise, if I was actually tested for cannabis in my system and the tests indicated that it was indeed in my system at the time I took possession of the firearm, then that would similarly be a slam dunk case.

(I guess even in the latter case I could maybe argue "yeah, I was an unlawful user, but I quit before buying the gun", but that defense is pretty weak if it's still in my system; I reckon it'd be stronger if I was sober for an actually-significant amount of time.)

Barring those? I ain't a lawyer, either, but my personal understanding is that the present-tense wording leaves a loophole big enough to drive a truck through it. Obviously the safest bet is to not rely on that being the case, but it's pretty easy to answer "No" to "Are you an illegal user of or addicted to any controlled substance?" without it being a felonious lie.

> or possess in or affecting commerce

Doesn't this mean that the prohibition of using such substances doesn't apply just to the moment of purchase, but to the whole period of time that you posses a firearm? I'm not a lawyer either and I'm not even American, but this is how I would interpret it. Also it would make little sense to have a law saying that you can't be a user of illegal drugs at the moment of purchase of a firearm, but you can start using such substances afterwards.

It would apply as it pertains to being "in or affecting commerce"; it'd be quite the stretch to apply that to possession outside the immediate context of a purchase/sale/transfer, though I suppose it wouldn't be the first time the Feds abused the ever-loving hell out of the Commerce Clause. Maybe taking a gun across state lines while high would qualify?

> Also it would make little sense to have a law saying that you can't be a user of illegal drugs at the moment of purchase of a firearm, but you can start using such substances afterwards.

The law in question derives from the federal government's Constitutional authority to regulate interstate and international commerce, which is (I would guess) why the language fixates on that aspect. The federal government doesn't otherwise have the power to infringe on the Second, Fourth, and (possibly) Tenth Amendments - as would likely be necessary to federally require gun owners to submit to random drug tests over something that one's state has made legal.

Meanwhile, my state (last I checked) has laws on the books separately prohibiting intoxication (be it via cannabis, alcohol, or whatever) while in possession of a firearm; to my knowledge, most (all?) states do.

So in the end using drugs while possesing a firearm makes it worse, it's just that those aren't federal laws but still apply.

Read up on Jeremy Kettler's attempt to avoid interstate commerce and also Wickard v Filburn. You probably know about the latter but not the former.

If growing your own plants with nothing but seed and material from the earth on your property, and then feeding it to your local animals is interstate commerce.... then it's hard to imagine any firearm even if made of iron pulled from the earth underneath you and machined on site and never sold to anyone or hell even fired could be considered to not have interstate nexus.

Those are what I was alluding to when I said "it wouldn't be the first time the Feds abused the ever-loving hell out of the Commerce Clause" :)

Both those cases entailed the defendants manufacturing something, which would be where the Feds would claim jurisdiction via their jurisdiction over interstate commerce. It's harder to make that argument w.r.t. something after a retail sale has already concluded (i.e. after the interstate commerce has happened). I wouldn't doubt the Feds would try to assert that literally everything that ever happens is or pertains to "interstate commerce", but that'd be sufficiently broad as to invalidate all sorts of other judicial precedents if actually held up in court.

Wait until you read the gun free school zone act, which seemingly makes it interstate commerce merely to be on a public property proximal but not on school property, no matter you have no intent to interact with the school or the school property in any way.

I recommend you consult a lawyer. Always understand the difference between "the law can be flouted and probably safely gotten away with so long as I don't piss off anyone powerful" and "this is legal."

That's the thing: as written, the law puts everything short of "I was literally high at the time I took possession of the firearm" in the "this is legal" category.

This of course only pertains to federal law; states have their own laws, and said laws usually prohibit being armed while intoxicated - regardless of the legality of the intoxicating substance.

Once again, because I am not a lawyer I cannot give you specific legal advice for your situation.

I strongly, strongly believe you are overconfident in your interpretation, particular when I read the provisions regarding possession which may be a seperate crime from say what was written on the 4473 at the FFL.

But I'm not the one you have to convince. I pray you are never in a position you must do the convincing.

I do not believe I am an authoritative enough of a professional to convince you, even were it that I had time to type a more complete explanation. Again I recommend you consult a lawyer, and preferably one that has worked in this area. My opinion as a rando on HN has no legal bearing on the justice system.