I don’t live in MD but I want to sell a 16” upper to someone that lives there. Is this legal?

uppers are not regulated

it may only be an issue for them if they put it on a lower and it creates a banned weapon
if anyone even notices

Anything goes for a pre-2013 lower, post-2013 lowers need an "HBAR"-stamped barrel or be assembled as a pistol.

Kharn

Yes, it is legal for you to sell the upper to a MD resident. Uppers are non-regulated.

The comments above mine allude to the buyer's conduct, in that we suffered a "firearm safety act" in 2013 that disallows lightweight uppers on post-2013 lowers. If the buyer has a pre-2013 lower, he can put any kind of legal-length upper on it, as the lower is grandfathered in and can legally receive a lightweight upper. If the buyer has a post-2013 lower, he is not allowed to make a banned firearm out of it by adding a lightweight upper.

This is all rather esoteric and serves only as another toe-hold to incrementally infringe the citizen's 2A rights, and is so difficult to enforce that enforcement will likely only occur as an add-on offense if something else happens. Because of enforcement challenges, and the obvious conflict with the US Constitution, many folks don't pay much attention to this latest bullshit by Maryland's General Assembly (of asses).

The buyer's conduct following the sale has nothing to do with you, as a seller.

I live in Virginia, but I have a brother living in Maryland and he'd like to put an AR15 together. So I'm trying to figure out the laws and what's legal. I'm just beginning to research this for him, and being a member here for the past 3 or 4 years, this is my first stop and this thread seems to be basically about what my question is about, so I won't start a new thread.

So if I'm understanding correctly, he can legally build an AR15 as long as the barrel is marked HBAR? Does it have to be a 20" barrel or can he use a 16" if he so desires? Also, is there a magazine limit? I seem to remember something about that, in the news.

Any barrel marked or marketed as "heavy barrel," "hbar," or being approximately 0.750" under the hand guards suffices for 5.56 in any barrel length. The SOCOM profile is acceptable. For other calibers, there's no restriction and everything is legal.

No mag transfers inside MD over 10 rounds, but possession and importation are not banned.

Kharn

So, if my brother decided on an AR-10 instead of an AR-15, he wouldn't have the barrel restriction (other than not being an SBR)? As for the magazine, if I understand that, he could visit me and go home with a 'gift' and it's ok, or would that 'gift' be considered 'importation'?

An AR10 is not an AR15, the only restriction is pick one of a flash suppressor, grenade launcher, or folding stock. Two or more is banned.

However he acquires the magazines out of state is not MD's concern, as long as he is the one that drives them into MD. You'll see very carefully worded shipping policies on some sellers websites, while others say no sales to MD residents.

Kharn

Thanks for the info. I don't know if he has his heart set on an AR15 or if an AR10 might suffice. He won't care about the grenade launcher or folding stock, so he won't want/need two or more. A 10 round mag may even be sufficient for him, but having options is always best.

I assume that an 80% is 'evil' in Maryland, so I won't even suggest that as a choice, not that he'd want to do a full on 'project' like that.

80%s are still ok.

Kharn

Oh, are they? That surprises me, for Maryland, anyway. I'll have to give him that option, though I'm sure he won't want to go through that work. Do they need to be engraved and serialized?

Just a thought I had, does Maryland consider a retractable stock to be a 'folding' stock? I wouldn't think that they would, but I wouldn't put anything past them.

So is a law folder off the table?

Folding requires a hinge.
A retracting stock does not hinge.

They had to drop the listing of telescoping stocks and numerous other features in order to get the '13 ban to pass.

Kharn

MD tried to ban future production, requiring all in existence to be serialized by an FFL for an unstated fee, but it did not pass before the legislature cut their year short and fled town. They were also going to ban possession of any firearm containing a 3d printed component or the plans to print the component or the distribution of those plans, it was in the same bill.

Currently no registration or marking is required. But be prepared to throw the receiver in the Bay come 1 July 2021, the day laws become effective from the 2021 legislative session. Lowers are handled (for all practical purposes in MD) the same as handguns, your friend should stock up and document his multiple pistol builds.

Kharn

No.

But you would need to have a muzzle brake instead of a flash hider, so as to avoid the 2 of 3 rule.