1. No, it is the default bedroom and the other guns work fine.
2. No, I've used this script for other guns.
3. I lowered the speed so low that I walk faster than it.
4. Collision mesh? If your talking about the colors that I used when I made the bullet model, they work fine. (P.S I tried the default bullet with it as well.)
5. No, every other gun works fine.
P.S I've managed to get it to work but it only collides with bricks/walls that are far away. (I've used this script for a few sniper rifles and it worked fine, but this isn't a sniper rifle.)