When they choose to carry 'high capacity magazines', SBRs (real pia to get for non-leo) - and other weaponry, it is understood these things help them be safer...
If grandma is not allowed to be safer because random bad guy - you have to wonder, or should maybe.
It's not that bad.
The easy way is to find an SBR you want to buy, file Form 4 for $200, wait for a few months, then take receipt of your NFA item.
Or if you want to do a conversion from an existing rifle, file Form 1 (also $200) and get short barrel. The disadvantage is that you've then created an NFA weapon, so you'd have to be more careful how you handle transfer and sale.
If you don't want an NFA SBR, well, AR-15s can be pistols. Pistols can be short. Pistols can't have buttstocks, but there are legal products that are not "intended" to be used as stocks. They happen to look just like a stock, but they're totally intended to be used as an arm brace. If you do use one as a buttstock, that's not how it was intended to be used, but it is legal to do so. This approach is so popular that ATF has issued letters saying it's not illegal.
Here's most of what you need to know: http://preparedgunowners.com/2017/04/27/atf-reverses-opinion...
It's not mentioned in the article, but pistols cannot have a forward grip, as that would make them "Any Other Weapon", which is NFA. If you have a forward grip but don't have the tax stamp, you'll go to prison. Keep in mind you can start down the AR-15 pistol route, then later get your Form 1 tax stamp to convert it into a rifle by attaching a stock.
This is all quite ridiculous, but that's the law.
Incidentally, I'm pretty sure this applies even if the grip isn't attached, or is attached to another gun. All depends on how friendly the ATF is feeling...
I think it's unlikely (but possible) a case would be brought against you for just having the grip, and I'm not sure if that's ever actually happened. As opposed to if you had all the parts to make a machine gun, where there could only be one use for those parts.
Also interesting, drilling the extra hole in your AR-15 lower so that it could some day accept an auto-sear is a serious felony, even if you don't own the auto-sear.
I'm fascinated by how insane these rules are after I learned that I can't legally own or operate a firearm because I'm a medical marijuana user. If cannabis ever gets unscheduled, I'd like to build a little arsenal.
I think your comment shows a fundamental misunderstanding.
My point was that some of the 'assault rifle bans' are trying to stop simple things like a grip addon, a collapsible stock, an over 10rd magazine - any one of those things could make the whole thing illegal..
and I would want grandma to have access to those things, all of them. It would make her, and her neighbors safer.
This is not fictional in any way shape or form.
Not too long ago a grandma near me went to take the shooting class with a 38 revolver.. it hurt her wrists after a few shots and everyone quickly realized she would not be able to perform the amount of firing to do the practice and the test with one.
If she had been given a police issue SBR MP5 with muzzle break, forward grip, collapsible stock, laser and red dot - she would be able to plink accurately all day long.
These things they want to ban are actually safety features - but people can't see that.
I may have to make a few grandma videos to show this maybe.