what spine arrow for 70 pound bow

3 min read 27-12-2024

Choosing the right arrow spine for your 70-pound bow is crucial for accuracy, safety, and maximizing your shooting experience. Using the wrong spine can lead to poor grouping, damaged equipment, and even injury. This guide will help you understand arrow spine and select the best option for your setup.

Understanding Arrow Spine

Arrow spine refers to the arrow's stiffness or flexibility. It's measured by how much the arrow bends under a specific load. A higher spine number indicates a more flexible arrow, while a lower spine number indicates a stiffer arrow. The spine you need depends on several factors, including your bow's draw weight, draw length, and the arrow's weight.

Key Factors Affecting Spine Selection:

Bow Draw Weight: Your 70-pound bow requires a relatively stiff arrow. Too flexible an arrow will bend excessively upon release, leading to inaccurate shots and potential damage to the bow.
Draw Length: Longer draw lengths generally require stiffer arrows. A longer draw length puts more stress on the arrow during release.
Arrow Length: Longer arrows need a stiffer spine to compensate for the increased length. Shorter arrows can use a slightly more flexible spine.
Arrow Material: Different arrow materials (aluminum, carbon, wood) have different inherent stiffness levels. Carbon arrows are generally more common for higher draw weights due to their strength and lightweight properties.
Point Weight: Heavier arrow points increase the overall arrow weight and affect spine. Heavier points generally require a stiffer spine.

Determining the Right Spine for Your 70-Pound Bow

Several methods exist to determine the correct spine for your 70-pound bow:

1. Using an Online Spine Chart or Calculator:

Many online resources offer spine charts or calculators. These tools allow you to input your bow's draw weight, draw length, arrow length, and point weight to determine the recommended spine. Always double-check the results and consider manufacturer's recommendations.

2. Consulting with an Archery Professional:

Archery shops often have experienced professionals who can assess your setup and recommend the appropriate spine. This is an excellent way to receive personalized advice and ensure you make the right choice. They can measure your draw length and offer hands-on assistance.

3. The "Spine Testing" Method:

This involves shooting several arrows with different spines to see which groups best. It's less precise but provides valuable feedback. However, it is best to consult a professional before attempting this method, to avoid damage.

Common Arrow Spine Ratings and Their Applications:

Spine ratings are usually expressed in numbers (e.g., 300, 400, 500). A lower number indicates a stiffer arrow. For a 70-pound bow, you'll likely need an arrow with a spine rating in the lower range (e.g., 300-400). However, this varies depending on the factors listed above. Always refer to the manufacturer's guidelines and spine charts.

Choosing the Right Arrow Material:

Carbon Arrows: Carbon arrows are very popular because they are lightweight, strong, and durable. They provide high performance and excellent accuracy for various bow draw weights. Carbon arrows come in various spine ratings, making them versatile for different bows.
Aluminum Arrows: While less common at high draw weights, aluminum arrows offer a good balance of strength and affordability. Aluminum can be a good option if you are working within a specific budget.

Important Considerations:

Arrow Length: Ensure that your arrow length is appropriate for your bow and draw length. An improperly sized arrow can negatively affect spine performance.
Fletching: Your arrow fletching also contributes to arrow flight characteristics. This is an important element to consider once you've determined the correct spine.
Safety: Always prioritize safety when choosing arrows. Using the wrong spine can damage your bow or cause injury.

Conclusion:

Selecting the correct spine arrow for your 70-pound bow is vital for accuracy and safety. By considering the factors outlined in this guide and utilizing available resources, you can ensure that you choose the best arrows for your setup and enhance your archery experience. Remember, consulting with an experienced archery professional is always recommended.