Okay, here's the gun I'm trying to measure the muzzle velocity of. It's a brake barrel. It takes 22 caliber pellet. And here's the setup. I basically constructed a pendulum that hangs in front of this protractor here. And the end of the pendulum is a ball of clay. And what I can do is fire the gun point blank into the ball of clay. And it causes it to swing. And then I can measure the arc length of that swing. Because I know how long the pendulum string is. And I know the mass of the ball. And I can approximate the mass of these pellets, but I don't have a very good scale. And basically the pellet from this gun doesn't wedge very far into the clay. It goes maybe half a centimeter into the clay. So it's a pretty inelastic collision. And thanks to the conservation of momentum, I can know the momentum of the ball after the collision. And so I can determine the approximate velocity of the pellet coming out of the gun. But it's very simple. There's a couple pieces of wood. And a protractor that I printed off the internet. And a ball of clay.