The Killer Instinct Lethal 405, while a powerful crossbow, is not without its fair share of problems. 

One of the main issues users have encountered is the durability of certain components. Some have reported that the limbs of the crossbow tend to crack or break after prolonged use, leading to a loss in accuracy and overall performance. 

Additionally, there have been complaints about the trigger mechanism, as it can be prone to jamming or misfiring, causing frustration and potentially dangerous situations. 

Another common problem is the scope’s reliability, with users experiencing issues such as fogging, poor illumination, or difficulty in zeroing in on targets. 

While the Lethal 405 offers impressive speed and performance, these reported problems highlight the need for careful consideration before purchasing, and the importance of regular maintenance and quality control in ensuring a smooth and trouble-free hunting experience.

Killer Instinct Lethal 405

The Killer Instinct Lethal 405 is a powerful crossbow designed for hunters who crave precision and performance. With a speed of 405 feet per second, this crossbow unleashes a lethal force that can take down any target with ease. 

Its compact design and lightweight construction make it easy to handle, allowing hunters to maneuver through any terrain with confidence. The Lethal 405 features an adjustable buttstock and foregrip, ensuring a comfortable and customizable shooting experience. 

Equipped with a 4×32 illuminated scope, this crossbow offers exceptional accuracy and clarity, even in low-light conditions. Its durable construction and advanced technology make the Lethal 405 a reliable and deadly weapon of choice for hunters seeking the thrill of the hunt.


Here are the specifications of the Killer Instinct Lethal 405 crossbow:

  • Speed: 405 feet per second
  • Kinetic Energy: 134-FT-LB
  • Trigger: 3.5-lb pull weight
  • Width: Cocked 14.75 inches, Uncocked 18.75 inches
  • Length: 34.5 inches
  • Weight: 7.2 lbs
  • Draw Weight: 220 lbs
  • Power Stroke: 14.5 inches
  • Camo: Brown Stock/True Timber Strata Camo Limbs


The Killer Instinct Lethal 405 crossbow offers several features, as mentioned in the search results:

  • Lightweight Composite Frame: The crossbow has a lightweight composite frame that provides durability and ease of handling.
  • Adjustable X-Lok Foregrip: It features an adjustable X-Lok forearm piece, which allows for maximum comfort and control.
  • 4×32 Non-Illuminated Scope: The crossbow comes with a 4×32 non-illuminated scope for improved accuracy and target acquisition.
  • Included Accessories: The package includes various accessories such as a foot-stirrup, rope cocker, dead silent kit, 3-bolt quiver, and 3 premium 20-inch HYPR Lite arrows with field tips.
  • Compatible with Dead Silent Crank: The Lethal 405 is compatible with the Dead Silent Crank, which offers an easy and silent cocking mechanism.
  • High Speed: It has a speed of 405 feet per second, allowing for fast and powerful shots.
  • Over-Molded Grip: The crossbow features an over-molded grip, providing a comfortable and secure hold.
  • True Timber Strata Camo: The stock of the Lethal 405 is designed with True Timber Strata Camo, offering effective camouflage in various hunting environments.

These features make the Killer Instinct Lethal 405 crossbow a budget-friendly option with solid performance for both beginner and experienced hunters.

Killer Instinct Lethal 405 Problems


Real user Experiences

Here is a summary of the Killer Instinct Lethal 405 problems mentioned in the Amazon reviews:

  • Difficulty Sighting In: Multiple customers reported having difficulty sighting in the crossbow’s scope, even when adjusting it to the maximum elevation.
  • Limb Issues: Several customers mentioned problems with the limbs of the crossbow, including splintering, cracking, and breaking. This is a significant safety concern.
  • Scope Quality: Some users complained about the quality of the scope, indicating that it required replacement right out of the box or didn’t perform as expected.
  • Customer Service: A few customers expressed dissatisfaction with the company’s customer service, citing slow response times and lack of resolution for their issues.
  • Weight: One user mentioned that the crossbow was very heavy.
  • String Issues: There were reports of string breakage after just a few shots.
  • Assembly Problems: One customer mentioned difficulties in assembling the crossbow due to issues with screws not fitting properly.
  • Safety Concerns: Several users expressed safety concerns regarding the crossbow’s limb issues and the potential for injury.
  • String Fraying: A customer reported a frayed string and broken cam after one year of use.

Limb Cracking or Breakage:

Causes of Killer Instinct Lethal 405 Limb Cracking or Breakage:
  • Quality or design issues: Some users have reported that the limbs of the Lethal 405 crossbow are fragile and prone to cracking or breaking. This could be due to manufacturing defects, inadequate material quality, or design flaws.
  • Misuse or mishandling: Crossbows, including the Lethal 405, require proper handling and maintenance. Misuse, such as dry firing the crossbow or exceeding the recommended draw weight, can put excessive stress on the limbs and lead to cracking or breakage.
  • Extreme weather conditions: Exposure to extreme temperatures, humidity, or other weather conditions can affect the durability and performance of crossbow limbs. Over time, these conditions may cause the limbs to weaken, bend, or warp, increasing the risk of cracking or breakage.
  • Lack of regular maintenance: Failure to inspect the crossbow regularly and address any signs of wear and tear can contribute to limb issues. This includes checking for loose parts, damaged or missing components, and cracks or damage to the arrows.
Solutions for Killer Instinct Lethal 405 Limb Cracking or Breakage:

While it’s important to consult with the manufacturer or a professional for specific solutions, here are some general recommendations to address limb cracking or breakage issues with the Killer Instinct Lethal 405 crossbow:

  • Contact the manufacturer: If you experience limb cracking or breakage issues with your Lethal 405, it’s advisable to contact the manufacturer directly. They can provide guidance, support, and potentially offer solutions to address the problem.
  • Authorized replacement limbs: If limb damage occurs, it’s crucial to purchase authorized replacement limbs from the manufacturer. Using non-approved or third-party limbs may void any warranties and potentially compromise safety and performance.
  • Regular inspection and maintenance: To prevent limb issues, regularly inspect your crossbow for signs of wear and tear. Pay attention to the limbs, strings, and other components. If you notice any cracks, damage, or other abnormalities, take appropriate action, such as contacting the manufacturer or a professional for inspection and repair.
  • Proper storage: Store your crossbow in a cool, dry place away from direct sunlight or extreme temperature fluctuations. This helps maintain the integrity of the limbs and reduces the risk of damage caused by environmental factors.

Trigger Issues

Causes of Lethal 405 Trigger Malfunctions:

Here are some potential causes:

  • Mechanical issues: Trigger malfunctions can occur due to mechanical problems within the trigger mechanism itself. This can include issues such as worn-out parts, misalignment, or damage to the trigger components.
  • Improper maintenance: Lack of regular maintenance, such as cleaning and lubrication, can cause dirt, debris, or rust to accumulate in the trigger mechanism. This can affect the smooth operation of the trigger, leading to malfunctions.
  • Misuse or mishandling: Incorrect use or mishandling of the crossbow, such as applying excessive pressure on the trigger or improper cocking, can put unnecessary stress on the trigger mechanism and lead to malfunctions.
  • Defective components: In some cases, trigger malfunctions can be caused by defective or faulty components. This could be due to manufacturing defects or quality control issues.
Solutions for Lethal 405 Trigger Malfunctions:

Here are some general solutions that can be considered:

  • Contact the manufacturer or a professional: If you experience trigger malfunctions with your Lethal 405 crossbow, it is advisable to contact the manufacturer directly or consult with a professional crossbow technician. They can provide guidance, and support, and potentially offer solutions to address the problem.
  • Regular maintenance: Regularly clean and lubricate the trigger mechanism according to the manufacturer’s instructions. This helps prevent the buildup of dirt, debris, or rust that can cause trigger malfunctions.
  • Proper handling: Ensure that you are using the crossbow correctly and following the manufacturer’s guidelines for cocking, loading, and firing. Avoid applying excessive force on the trigger or using the crossbow in a way that can cause unnecessary stress on the trigger mechanism.
  • Inspect and replace components: Regularly inspect the trigger mechanism for any signs of wear, damage, or defects. If any components are found to be faulty or worn-out, consider replacing them with authorized replacement parts from the manufacturer.

Scope Issues

Causes of Lethal 405 Scope Issues:

Here are some potential causes to consider:

  • Misalignment: Scope misalignment can occur if the scope is not properly mounted or if it has shifted during use. This can result in inaccurate aiming and difficulty in sighting targets.
  • Loose Mounting: If the scope is not securely mounted to the crossbow, it can move or vibrate during shooting, leading to inconsistent accuracy and poor performance.
  • Defective Scope: In some cases, scope issues may arise due to manufacturing defects or quality control issues. This could include problems with the reticle, lens clarity, or internal components of the scope.
  • Environmental Factors: External factors such as changes in temperature, humidity, or air pressure can affect the performance of the scope. These factors can cause the scope to fog up, impair visibility, or affect the overall accuracy of the scope.
Solutions for Lethal 405 Scope Issues:

While specific solutions may depend on the nature of the scope issue, here are some general steps that can be taken to address scope issues:

  • Check Mounting: Ensure that the scope is securely mounted to the crossbow. Tighten any mounting screws or bolts as necessary, following the manufacturer’s recommendations. Consider using thread locker to prevent loosening of screws during use.
  • Align the Scope: Verify that the scope is properly aligned with the crossbow. Use a boresighter or follow the manufacturer’s instructions for aligning the scope with the barrel of the crossbow. This can help ensure that the scope is pointing in the same direction as the arrow’s flight path.
  • Inspect the Scope: Examine the scope for any signs of damage or defects. Check the reticle, lenses, and internal components for any issues. If you suspect a defect, contact the manufacturer for guidance on potential solutions or warranty support.
  • Consider Environmental Factors: Be mindful of environmental conditions when using the crossbow. Take precautions to prevent fogging or moisture buildup on the scope, such as using anti-fog sprays or covers. Additionally, make adjustments to compensate for changes in temperature or air pressure if needed.

String Issues

Causes of Lethal 405 String Issues:

String issues can be a common problem with crossbows, including the Killer Instinct Lethal 405. Here are some potential causes for string issues:

  • Wear and Tear: Over time, the string of the crossbow can experience wear and tear due to repeated use. This can lead to fraying, stretching, or even breakage of the string.
  • Incorrect Maintenance: Improper maintenance, such as failing to wax the string regularly or not properly storing the crossbow, can contribute to string issues. Lack of maintenance can cause the string to deteriorate and lose its integrity.
  • Poor Quality String: If the Lethal 405 crossbow comes with a low-quality or defective string, it may be more prone to issues such as fraying or breaking.
  • Misalignment or Misadjustment: If the string is not properly aligned or adjusted on the crossbow, it can cause uneven tension or stress on the string, leading to potential issues.
Solutions for Lethal 405 String Issues:

To address string issues with the Killer Instinct Lethal 405 crossbow, consider the following solutions:

  • Inspect and Replace: Regularly inspect the string for any signs of wear, fraying, or damage. If you notice any issues, it is recommended to replace the string with a high-quality replacement that is compatible with the Lethal 405.
  • Proper Maintenance: Follow the manufacturer’s guidelines for string maintenance. This typically involves regular waxing of the string to keep it lubricated and protected from the elements. Additionally, store the crossbow in a cool and dry place to prevent unnecessary exposure to moisture or extreme temperatures.
  • Align and Adjust: Ensure that the string is properly aligned and adjusted on the crossbow. If necessary, consult the manufacturer’s instructions or seek professional assistance to ensure that the string is correctly positioned and tensioned.
  • Use Quality Strings: Consider using high-quality strings that are specifically designed for the Lethal 405 crossbow. These strings are often more durable and less prone to issues like fraying or breaking.