ANECDOTE:
I came to Canada at 3 years old with first generation parent immigrants in the early 90's and we all had citizenship within ~3 years (I was 6 at the time).
In the rest of the world the "SLR" is referred to as a "FAL" and it's 7.62x51mm / .308 Winchester ammunition is a "medium" caliber firearm.
Quite a bit weaker than what was used commonly in WW1/WW2 but stronger than the standard 5.56mm / .223 Remington round that is used today by the armed forces. It's still a very common round and used in various applications around the world.
"Quite a long time" is a bit of fear pandering, it's what you would use to kill a deer humanely.
Any sort of a firearm is dangerous when used against people massed in tight quarters.
For those of us who ride road bikes, yes sub 20lb makes a big difference. My Fiancee's road bike with Sora components is just under 19lbs and that's pretty basic as far as a road bike goes.
It gets a lot more expensive once you go sub 14lbs, and very very expensive sub 10.5lbs or so. (20k+)
This is a multiyear process and extremely challenging for H4 holders.