What is Paintball Barrel Bore Size?

  • Updated July 28th, 2023

The paintball barrel is a critical component of your paintball marker, directly impacting the accuracy and performance of your shots. One crucial aspect of the barrel is its bore size, which refers to the internal diameter of the barrel. The bore size plays a significant role in paintball accuracy, efficiency, and consistency.

In this comprehensive guide, we will delve into the concept of paintball barrel bore size, its importance, how it affects your gameplay and tips for choosing the right bore size for your paintball marker.

What is Paintball Barrel Bore Size


Understanding Paintball Barrel Bore Size

The bore size of a paintball barrel is measured in thousandths of an inch or millimeters. It represents the internal diameter of the barrel through which the paintball travels. The most common bore sizes in paintball are .680, .685, .688, .690, and .693. Some barrel kits even offer interchangeable bore inserts that allow players to change the bore size to match their paintballs precisely.


Importance of Paintball Barrel Bore Size

The bore size of your paintball barrel is essential for several reasons:

1. Accuracy

The bore size affects how much friction the paintball experiences as it travels through the barrel. If the bore size is too tight, the paintball may experience excessive friction, leading to inconsistent shots, barrel breaks, and reduced accuracy. On the other hand, if the bore size is too large, the paintball may bounce around inside the barrel, also causing accuracy issues.

2. Efficiency

An optimally matched bore size can improve air efficiency by reducing wasted air and lowering the risk of ball breaks inside the barrel. A consistent bore size ensures that the paintball leaves the barrel with the right amount of air pressure, maximizing the use of available air and shots per tank fill.

3. Consistency

Consistency in paintball is crucial for accuracy and performance. A properly matched bore size helps ensure consistent velocity and shot-to-shot consistency, leading to a more reliable and predictable shooting experience.

How Bore Size Affects Gameplay

The impact of the bore size on your paintball gameplay can be significant. Let’s explore how different bore sizes affect various aspects of your performance on the field:

1. Accuracy and Precision

As mentioned earlier, the bore size directly influences the accuracy of your shots. A bore size that matches the paintballs you are using allows for a consistent and smooth trajectory, resulting in more accurate shots. An accurately sized bore reduces ball spin and wobble, enhancing the precision of your shots.

2. Air Efficiency

Using a bore size that closely matches your paintballs reduces the wasted air due to excessive friction or ball bounce. This improved air efficiency translates to more shots per tank fill, allowing you to stay on the field longer without the need for frequent air refills.

3. Barrel Breaks

Barrel breaks occur when paintballs break inside the barrel, obstructing the paintball’s path and negatively affecting accuracy. A properly matched bore size minimizes the likelihood of barrel breaks, contributing to a smoother and more enjoyable gameplay experience.

4. Consistency in Shots

A consistent bore size ensures that each shot leaves the barrel with the same level of force and velocity. This shot consistency is essential for players who rely on muscle memory and consistent aim for accurate shooting.

Tips for Choosing the Right Bore Size

Selecting the right bore size for your paintball marker involves understanding your paintballs, playing style, and field conditions. Here are some tips to help you choose the appropriate bore size:

1. Consider Your Paintballs

Start by examining the paintballs you will be using. Check the diameter of the paintballs and compare them to the available bore sizes. Look for a bore size that is as close as possible to the paintball diameter for the best match.

2. Test Different Bore Sizes

If possible, test your paintballs with different bore sizes to see which one provides the most consistent and accurate shots. Some paintball fields or pro shops may have bore sizing kits available for testing.

3. Adjust for Weather Conditions

Keep in mind that weather conditions, especially temperature, can affect paintball size. In colder weather, paintballs may shrink slightly, while they can expand in hotter temperatures. Adjust your bore size accordingly to accommodate these variations.

4. Consider Field Conditions

Field conditions, such as the type of paintballs used on the field, can also influence your bore size choice. If the field uses a specific brand or size of paintballs, consider matching your bore size to those paintballs for optimal performance.

5. Invest in a Barrel Kit

If you regularly play in different conditions or use various paintballs, consider investing in a barrel kit that includes multiple bore inserts. A barrel kit allows you to change the bore size to match different paintballs or field conditions, ensuring versatility and optimal performance.


How to Measure Bore Size

If you want to measure the bore size of your paintball barrel, you can use a bore sizer. A bore sizer is a set of graduated metal rings or gauges that allow you to measure the internal diameter of your barrel. Simply slide the different bore sizers into your barrel until you find the one that fits snugly without being too tight or too loose. The size of the bore sizer that fits best corresponds to the bore size of your barrel.


Final Thoughts:

The paintball barrel bore size is a crucial factor that directly affects the accuracy, efficiency, and consistency of your shots. Choosing the right bore size for your paintball marker involves considering your paintballs, field conditions, and playing style. A properly matched bore size allows for accurate shots, improved air efficiency, and a more consistent shooting experience on the paintball field.

When in doubt, don’t hesitate to seek advice from experienced players or professionals who can provide valuable insights and recommendations. Remember that experimenting with different bore sizes and practicing with consistency are essential in finding the optimal bore size that suits your paintball playstyle and preferences. By understanding the significance of the bore size and making informed choices, you can elevate your paintball game and become a more accurate and successful player on the field.