You should watch the first half hour or so of this hearing to get more details.
https://www.youtube.com/live/BNNFneRw3rk?feature=shareSynopsis:
1. The National Firearms Act of 1934 (NFA) in part tried to ban handguns for the general public because they were too easily concealed making them useful in committing crimes. When the courts said they can't do that, some of the ATF rules that implemented that objective -- like defining a short-barreled rifle as more dangerous than a rifle with a 16" barrel -- remained on the books. It's not hard to buy a rifle or shotgun and turn it into an SBR or sawed-off shotgun with a hacksaw. But, feelings matter more than logic. As a compromise to banning machine guns and SBRs, they implemented the registration system for NFA controlled items. The $200 tax in1934 was a sizable amount for most, roughly equivalent to $4,500 today. The intent was to make it financially nonviable for the majority of gun owners to legally possess such firearms.
2. Given the reality of new changes in technology for firearms, it's ridiculous to continue treating rifles with a 14.5" barrel as a greater risk to public safety than one with a 16" barrel, especially when compared to the bullpup designs of rifles and shotguns. The barrels are still 16"+, but the fire control groups were moved forward to make the overall length just within legal limits making them very easy to conceal. Nobody in DC seems to be worried about that. Also, a 16" barrel tends to increase the velocity of the bullet compared to a shorter barrel. Again, their reasoning is in direct opposition to common sense.
3. Over the last 10 years, the manufacturer of the original pistol brace says he created it for a wounded vet and friend. The brace allows him to have an additional point of contact with the pistol without using 2 hands.
4. Although the brace looks very similar to a rifle stock, it has features for attaching to the forearm. Each time the design was updated, a sample was sent to the ATF, and each time the ATF said the same thing: a pistol brace does not turn a pistol into a short barreled rifle, nor is the pistol with a brace an NFA-controlled item. They even said in an opinion letter that someone who happens to shoulder the brace-equipped pistol doesn't change the design nor intent of how a pistol brace is to be used.
5. Under Biden, the ATF did a complete 180 on their previous decisions for the past decade, not only making the brace an NFA item, but any pistol with a brace without a tax stamp and proper NFA registration is considered an illegal SBR subject to a felony arrest, up to 10 years in prison, and a fine of up to $250,000. of course, a felony conviction would also make you ineligible to buy, own or possess firearms for the rest of your life.
6. It's estimated that some 14 million braces are in circulation. The number could be as high as 40 million. That means many millions are at risk of a felony conviction after the rule takes effect in May.
7. The brace itself makes a legal pistol into a larger weapon, making it LESS able to be concealed. It's about as long as an AR stock, but it's also bulkier than one. There is no rational justification for treating the brace as they are if the intent is to avoid concealment.
8. Without the brace, millions of users will no longer be able to go to the range or participate in sporting events because they are physically unable to wield a pistol without a brace.
9. Congress created the NFA, not the ATF. Our elected representatives should be the ones creating any new bans of such accessories, not an administrative, bureaucratic agency under the Executive Branch.
In short, the ATF is overstepping their authority by making new, contradictory rules that carry the weight of law not for public safety, but to create a technicality that deprives legal owners of their property and threatens a felony arrest for noncompliance.
There are tons of articles and videos detailing the new rules online. So far, i've yet to see a coherent argument that gives any evidence that the SBR itself is a threat and requires control by the NfA and ATF. Similar to suppressors, it's about feelings, not reality.
Do you know the origins of the NFA? Look up the St. Valentine's Day Massacre, Chicago 1929. Although 2 shotguns and 2 Thompson machine guns were used, only the machine guns were placed on the NFA control list. This was a result of public fear and the association drawn between machine guns, pistols and gangsters.