Reloading 101 - Part 4, Crimping, Inspection/Quality Control

To wrap up the stages of reloading, here are Steps 13 and 14 as promised. This section is short — both steps are straightforward and mainly about choosing the right approach and checking your work.

13. Crimping
What is crimping — Crimping compresses the case mouth around the bullet so it’s held securely in place. Its purpose is to prevent bullet movement during feeding or recoil and to reduce the risk of pressure spikes from bullet setback.

When crimping is used — Crimping is commonly applied for high-recoil loads, cartridges destined for tubular (tube-magazine) firearms, and bullets that have a cannelure (the circumferential groove on the bullet). By contrast, many match-grade target loads are intentionally left without a crimp because any deformation can harm precision. The decision to crimp should be based on the cartridge, bullet design, and authoritative load data.

Bullet cannelure — A cannelure is the groove around a bullet’s circumference that can accept a roll crimp. Bullets with cannelures are often crimped into that groove to provide a secure mechanical lock.

Factory vs. Taper vs. Roll crimps

• Factory Crimp: Some manufacturers (Lee and others) offer a dedicated die that produces a factory crimp - a collet-style die that squeezes the case mouth into the bullet’s cannelure for a strong mechanical lock. Many reloaders find a factory-crimp die especially useful for certain calibers — for example, .30-30 and .45-70 — where a secure roll crimp improves feeding and durability in tubular magazines or high-recoil applications. Some reloaders use the factory-crimp die as a separate operation after bullet seating; others incorporate crimping into a combined seating/crimping step depending on their equipment and preferences.

• Taper crimp: Compresses the case mouth around the bullet’s ogive. Typically used on semi-automatic handgun rounds and on bullets without cannelures to help maintain consistent overall length and reliable feeding.

• Roll crimp: Folds the case mouth into a bullet’s cannelure, creating a stronger mechanical lock. Commonly preferred for revolver cartridges and for rounds used in tubular magazine firearms (e.g., many lever-action rifles).

(Image below shows an uncrimped round beside a tapered-crimp 9mm, and a set of .38 Special rounds with roll crimps — illustrative photos only identification, not as an instruction.)

14. Inspection & Quality Control
Perform a consistent visual and dimensional inspection of finished rounds before they are used or stored. Look for signs of improper seating, visible deformities, inconsistent overall length, loose bullets, or other defects that could affect safe function. Segregate any suspect cartridges for corrective measures and keep clear records of components. Verify periodically that tools and equipment are functioning consistently and consult reputable load manuals or qualified instructors when uncertain. I typically inspect every five rounds during loading and recheck the entire batch when finished.

Remember, this step was also mentioned in Part 1 of this series in Step 1 of the Case Preparation.