
As you delve into the world of firearms, the concept of excess bullet setback could potentially leave you feeling alarmed. In the eye-opening video, “Smyth Busters: Will Excess Bullet Setback Blow Up Your Gun?”, shared by Brownells, Inc., hosts Stephen and Caleb put this widely held belief under scrutiny. They deconstruct the notion of bullet setback, explaining it as a circumstance where the bullet is retracted into its case, often caused by continuous recurring impact with the feed ramp while loading or unloading a firearm.
The video does not hold back in warning viewers about the potential dangers associated with this phenomenon. Amplifying the fear factor, the hosts make it clear that bullet setback indeed poses a risk to your firearm, particularly when you’re hand loading rounds for pistol calibers with less room inside the casing. The consequences can extend from an increase in chamber pressure causing substantial damage to your gun to severe feeding problems in self-defense circumstances. Armed with this information, viewers will be well placed to avoid the potential pitfalls associated with excess bullet setback.
Understanding Bullet Setback
Definition of bullet setback
Bullet setback occurs when the bullet in a cartridge is pushed deeper into the case than its standard position. It’s named after the fact that the bullet is ‘set back’ into the cartridge, a development derived from the bullet coming into contact with a foreign object, most commonly, the feed ramp of a firearm.
How bullet setback occurs
The most common cause of bullet setback is the repeated process of chambering and unloading a round. Each time you load the round, the bullet can impact the feed ramp, and over time, gradually, it can be forced further back into the casing. A common instance where this happens is with a carry gun, which you might unload every night and load up again the next morning.
Visual comparison between normal cartridge and setback cartridge
When you compare a normal cartridge and a setback cartridge, the difference is evident. A regular cartridge has the bullet properly positioned at the mouth of the case. In contrast, a setback cartridge has the bullet visibly recessed into the case.
Causes of Bullet Setback
Repetitive chambering and unloading
Repeatedly chambering and unloading the same round can lead to bullet setback. This action exposes the round to the feed ramp numerous times, and assuming that there’s a hard impact, the bullet may gradually push back into the case.
Effects of hitting the feed ramp repeatedly
The more times a bullet hits the feed ramp, the higher the chances of a setback because this process places force on the projectile, causing it to move back into the case.
Connection with hand loading for pistol calibers
In situations where hard loading is carried out, particularly for pistol calibers like the 9mm, bullet setbacks can also take place. This happens because there isn’t much room in the casing during hand loading, thereby heightening the chances of compressing the bullet, which can eventually lead to a setback.
Consequences of Bullet Setback
Potential to cause gun explosion
One of the many adverse effects of bullet setback is the increased risk of a gun explosion. This happens because the setback can cause a spike in chamber pressure when the round is fired, leading to potential catastrophic failure of your firearm.
Increased wear and tear on the firearm
Even if the situation doesn’t escalate to an explosion, bullet setback also significantly enhances the rate of wear on your firearm. This is because it increases pressure, putting undue stress on firearm parts and accelerating wear and tear.
Interference with proper feeding mechanism resulting in firing and clearance problems
Bullet setback can also upset the proper feeding mechanism of your firearm, subsequently leading to firing and clearance issues. For instance, if a setback bullet cannot chamber correctly, it might not even get to the firing stage due to feeding problems.

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Increased Chamber Pressure due to Bullet Setback
Reasons for chamber pressure spike
When a bullet setback occurs, it can cause a surge in chamber pressure because it compresses the charge. The elevated pressure can cause severe damage to your firearm.
Risks associated with running max loads
When running max loads, if bullet setback occurs, it can raise the pressure even further. As most firearms are safety tested for their running pressure, higher pressures can ultimately lead to gun damage.
Increased pressure from setbacks in plus p plus loads
The setbacks are even more of a concern in plus p plus loads since the bullet setback can cause chamber pressures to increase to dangerous levels.
Gun Safety Around Bullet Setback
Variations in safety testing of different guns
Not every firearm on the market goes through the same rigorous safety testing. While most are tested to take pressures way above their running pressure, bullet setback can push guns to their limit, causing them to fail.
Overview of safety factors in the operation of firearms
Considering potential bullet setbacks and understanding the mechanism behind it is a significant safety factor when operating firearms. Ignoring the possibility of a bullet setback can have severe consequences, including possible bodily harm if the firearm explodes.
Specific gun types dealing better with setbacks
Some gun types are less prone to setbacks than others due to the way they feed rounds into the chamber. For instance, firearms that feed cartridges more linearly, like Glocks and Beretta 92s, are less prone to setbacks compared to those with a more angled feed ramp.
Impact of Bullet Setback on a Firearm’s Performance
Changes in the case structure
Bullet setback can alter the case’s structure. Because the interior of cases often taper, when the bullet gets pushed back, it can cause the case to expand. This deformation can create potential feeding problems and may not even get to the firing stage.
Problems with bullet entry into the chamber
Bullet setback can cause feeding difficulties in the firearm and result in the round not entering the chamber correctly. This misalignment can cause issues with firing as it changes the firearm’s precise mechanics.
Effect on the gun’s accuracy
Bullet setback can also negatively impact the firearm’s accuracy. This effect arises because setbacks can alter the jump of the bullet (the distance it travels from the cartridge to the rifling), leading to shot inconsistency.
Bullet Setback in Various Calibers
Prevalence in both pistol and rifle calibers
While setbacks occur more often in handload pistol calibers because of the casing’s limited room, it’s crucial to note that they are not exclusive to them. Bullet setbacks can also occur in rifle calibers, although these tend to have more room inside their cases.
Comparing the likelihood of setbacks in pistol versus rifle calibers
The configuration of pistol calibers increases the likelihood of bullet setback. But it doesn’t undermine the fact that setbacks can occur in rifle calibers too when exposed to similar feeding conditions.
Implications of bullet setback in high pressure calibers like 9×23 and 10mm
Bullet setback in high-pressure calibers, such as 9×23 and 10mm, can be particularly dangerous. Although these rounds can handle higher pressures, bullet setback can push these calibers to their limits, potentially leading to detrimental effects like a gun blow.
Avoiding Bullet Setback
Best practices in loading and unloading guns
The best way to prevent bullet setback is by following good gun handling practices. For instance, regularly cycle the chambered round in your carry gun instead of unloading and reloading the same one repeatedly.
Proper ways to handle guns showing signs of bullet setback
If you notice any signs of bullet setback, the proper course of action is to dispose of the affected round. Continual usage of setback ammunition can lead to damaging the gun or even causing personal injury.
Precautions during hand loading
If you hand-load your ammunition, always ensure that the bullets are crimped correctly into the case and check regularly for signs of bullet setback. Additionally, mixing casings with different wall thicknesses during hand-loading may result in different tensions on the bullets, increasing the risk of bullet setback.
Bullet Setback in Self-Defense Scenarios
Feeding problems in self-defense scenarios
In high-stress scenarios like self-defense situations, a bullet setback can lead to catastrophic failure as feeding problems can prevent the firearm from firing.
Risk of single shot firing capability due to bullet setback
In a setback scenario, a jammed round may leave you with only a single-shot capability in a self-defense situation.
Clearance difficulties with jammed rounds
Furthermore, clearing the firearm in the event of a jam may be extremely difficult due to the setback round swelling and sticking in the chamber.
Conclusion
Recognizing the plausibility of gun damage due to bullet setback
It’s crucial to be aware that setbacks are very much a real occurrence, and can lead to severe damage to the firearm, or even cause an explosion in extreme cases. It’s not a myth but a reality that every firearm user must be aware of.
Importance of vigilance in spotting bullet setbacks
Being vigilant in spotting signs of bullet setbacks and properly handling ammunition is a pivotal part of gun safety. Regular maintenance, along with appropriate loading and unloading practices, can help prevent this potentially dangerous occurrence.
Emphasis on user safety and protection against setbacks
Ultimately, the emphasis should be on user safety and safeguarding against setbacks. Whether hand-loading or frequently chambering a firearm, one should always be proactive about correctly handling ammunition, particularly with high-pressure calibers.




