1. 16-1 Bullet and Cartridge Comparison
16 - Firearms, Tool Marks, and Other Impressions

2. rifling
The manufacture of a gun barrel requires impressing its inner surface with spiral grooves.

3. rifling
The manufacture of a gun barrel requires impressing its inner surface with spiral grooves.
This is a step known as rifling.

4. rifling
The manufacture of a gun barrel requires impressing its inner surface with spiral grooves.
This is a step known as rifling.

5. Why rifling?
Rifling gives spin to the projectile when it is fired.

6. Why rifling? Rifling gives spin to the projectile when it is fired.
This keeps it on an accurate course.

7. Why rifling? Rifling gives spin to the projectile when it is fired.
This keeps it on an accurate course.

9. Striations
No two rifled barrels have identical striation marks.

10. Striations
No two rifled barrels have identical striation marks.

11. Striation

12. Striation
The inner surface of the barrel of a gun leaves its striation markings on a bullet passing through it.

13. class characteristics
The class characteristics of a rifled barrel include

14. class characteristics
The class characteristics of a rifled barrel include
the number of lands and grooves

15. class characteristics
The class characteristics of a rifled barrel include
the number of lands and grooves

16. class characteristics
The class characteristics of a rifled barrel include
the number of lands and grooves
the width and direction of twist