You all sure Trump will Veto? He use to be a staunch Democrat, even supported Bill and Hitlery.
Trump is on the record saying "assault weapons" should be banned. From what I'm seeing, steps will go like this:
#1: Universal background checks
If the mass shootings of mostly middle to upper class people continue, especially in schools, we will get the following sooner than later:
#2: Magazine feed, semi-automatic function rifles will be banned from future manufacturing and retail sale
#2A: Magazines with a capacity of more than ten rounds will be banned from future manufacturing and retail sale
If the mass shootings still continue:
#3: All semi-auto magazine feed rifles will be required to be registered the same as full-automatic rifles.
#3A: Possession of magazines with a capacity of more than ten rounds will either require registration or be outright banned.
#3B: All semi-auto magazine feed rifles will be required to be stored securely, likely by being rendered inoperable or being in some specified container (safe).
These steps above don't "take anyone's guns away." What they do is drive the price for your typical AR, AK, etc. through the roof. Transfers will be minimal, but allowed. People will actually invest in alarm systems, good safes, etc. instead of putting three ARs in cases under their bed. This will likely significantly reduce mass shootings with semi-auto rifles.
No one is going to go and take action due to any laughable line in the sand being crossed. With the above, no ones guns are being taken. You'll still have your AR/AK/G3/whatever at home, in a safe, maybe with a bolt removed, etc.. Since transfers will be allowed similar to fully autos, no young person is going to "go to war" because their rights were violated.
Right now, the people that want semi-auto rifles have them. Anyone too poor to have purchased one over the last twenty years doesn't really have a complaint because if you don't have one now, when prices are as cheap as they are, such a person is likely to never have owned one anyway.
Other things that will come about, but likely more locally based:
-Ammunition regulation
-Semi-auto handgun regulation
-Quickly passed laws if some semi-auto rifles start being sold with "fixed" magazines holding more than ten rounds. Also, I could see some laws banning future produced bolt or lever action rifles from being able to use AR/AK etc. higher capacity magazines.
-Buy backs of semi-auto rifles and/or higher capacity magazines. They will offer $1,500 to $2,000 for a rifle. Some people will take the money.
The tide is already turning. Lots of people today want the government to raise them cradle to grave. Half of my left leaning Facebook friends want their only requirement for their personal safety to be they turn their deadbolt at night. They don't want to have to deal with any firearms. The other half would be perfectly content with just being allowed to own only revolvers for handguns and only fixed, low capacity magazine feed bolt and lever action rifles.