Smyth Busters: Will Excess Bullet Setback Blow Up Your Gun?

Published on March 15, 2022
Duration: 5:38

This video from Brownells experts Steve and Caleb addresses the myth of whether excessive bullet setback can cause a firearm to malfunction or explode. They explain how repeated chambering can push a bullet deeper into the case, increasing internal pressure significantly, especially in high-pressure cartridges like 9mm. The experts demonstrate that while a catastrophic failure is unlikely in most modern firearms, bullet setback can lead to feeding issues and potentially damage the firearm. They also touch on how firearm design, like the feed ramp geometry of a 1911 versus a Glock, influences the likelihood of setback, and emphasize the importance of proper neck tension and crimping for handloaders.

Quick Summary

Bullet setback occurs when a bullet is pushed deeper into a cartridge case, reducing internal volume and significantly increasing chamber pressure. This can happen from repeatedly chambering rounds, especially in firearms with steep feed ramps like the 1911. While not typically causing an explosion in modern guns, it can lead to dangerous pressure spikes, feeding failures, and firearm damage. Handloaders must ensure proper neck tension and crimping to prevent it.

Chapters

  1. 00:00Introduction to Bullet Setback
  2. 00:40Causes of Setback
  3. 01:16Pressure Risks
  4. 02:20Feeding and Case Issues
  5. 03:10Firearm Design and Handloading
  6. 04:08Rifle Calibers and Conclusion

Frequently Asked Questions

What is bullet setback and how does it happen?

Bullet setback is when a bullet is pushed deeper into the cartridge case than intended, often occurring from repeatedly chambering a round. This action can cause the bullet to strike the feed ramp, gradually pushing it back into the case and reducing internal volume.

Can bullet setback cause a gun to explode?

While a catastrophic explosion is unlikely in most modern firearms, significant bullet setback can drastically increase chamber pressure. This can lead to dangerous pressure spikes, case ruptures, feeding failures, or damage to the firearm, especially with high-pressure loads.

Does firearm design affect bullet setback?

Yes, firearm design plays a role. Pistols with steeper feed ramps, like many 1911 models, are more prone to causing bullet setback as the bullet repeatedly strikes the ramp. Firearms with more direct feeding paths, such as many Glocks, are generally less susceptible.

What should handloaders do to prevent bullet setback?

Handloaders must ensure proper neck tension when seating bullets and apply an adequate crimp. These steps help secure the bullet in place, preventing it from moving deeper into the case during chambering or recoil, which in turn mitigates the risk of increased pressure.

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