Your right. I'm wrong. You win. A bullet impacts with the 12-22 lbs of force that is felt in recoil. Magic causes it to knock people over and force themselves through people.
Please get your GED. I will provide rough calculations and give the bullet the benefit of the doubt when making assumptions. Unfortunately these will be lost on you because physics is magic to you, and what some NRA guy said is more important to you than fact.
Let's assume your linebacker is 220lbs, or 100kg. Let's assume he's running at you and you're standing still. 10mph is about 4.5 m/s. So he's coming at you with 100kg * 4.5m/s = 450kg*m/s of momentum.
A .45 (a big one) is 230grains, almost .015kg. We'll assume you're being shot at point blank range. The muzzle velocity is say 850fps or 259.08 m/s. So the bullet is coming at you with 3.885 kg*m/s of momentum.
Momentum is conserved, so assuming no loss of energy (the bullet loses a lot actually due to exerting a force outward inside the body, but I'll assume you have a metal plate on your chest), the equation would be
m(bullet)v(bullet) + m(you)v(you) == m(bullet)v(bullet) + m(you)v(you)
Where the left side is before impact and right side is after impact.
You have zero velocity to start, if you're standing still. If the bullet expands inside you when it hits, you and the bullet have the same velocity. I will assume you weigh as much as the linebacker.
3.885 kg*m/s = (velocity after impact)*(mass of you and bullet =still 100kg)
So velocity after impact, assuming all energy was used in pushing you (much wasn't), is .03885 m/s, = .12 ft/s, and that was being generous.
Same thing with the linebacker,
450kg*m/s = (velocity after impact)*(mass of both of you =200kg)
So velocity after impact = 2.25 m/s = 7 ft/s