ALRIGHT!!! ive figured out an EASY solution to this!
1. open your BL folder in the program files
2. go into the "add-ons" folder
3. go into the "shapes" folder
4. go down the list and find gunshell.dts AND bullet.dts
5. duplicate both of them(only gunshell if needed)
6. put the copies into the "shapes" folder of the weapon (minigun>shapes)
7. load up BL
8. enable in "add-ons"(not the folder)
9. ENJOY!
hope i helped! ^^(i am on a Mac though, so you might have to extract some more stuff)