Bullet casing improvements

There are various suggestions relating to bullet casings that I think would be cool to add:

1. Add shotgun shells (see image #1)

2. Make the velocity and angle of the ejected casings slightly random to mimic a proper ejection pattern when standing still, rather than just forming a spikey clump at a single point. (see image #2)

3. Make it to where casings lay perfectly flat on the ground when they stop moving, rather than having them leaning at weird/random angles and clipping through the floor. (see image #3)

4. Add an option to set the casing's life span. This would allow the user to decrease the life span to reduce visual clutter, or make the life span practically infinite for that ***Extra Immersion***.

5. Have the casing model's length, width, and height change depending on the caliber being fired. Ex: A gun in .45 would use the default pistol casing model at the default size, a gun in 9mm would use the pistol casing model but with the length, width, and height reduced by 15-20%, a gun in .50 AE would be the the pistol casing model but with the width and height increased by around 10% and the length increased by around 30-40%, ex. (see image #4)