How to break in an AR-15 Barrel
A step by step guide on how to break in an AR-15 barrel
Why break in a barrel?
When barrels are made, there are small imperfections that are left as a result of the machining process. These imperfections are often so minor that they can’t be seen with the naked eye. These imperfections could include microscopic nicks, pockets, shallow holes, and tool marks.
The goal of breaking in the barrel is to smooth out these imperfections that result from machining the barrel. The idea is to help fill in those imperfections and create a smooth even surface by removing anything that could impact the spin of the bullet in the barrel. This works by running a bare bullet by the bare barrel steel. This knocks down and smooths out those imperfections. The process of breaking in a barrel entails shooting a single round, cleaning the barrel, and repeating. The idea behind going through this process is it will increase accuracy while shooting, reduce flyers, and tighten groupings. It will also decrease copper fouling which affects accuracy. Copper fouling is when copper from the bullet sticks to the microscopic imperfections in the barrel. By knocking down and smoothing out those imperfections this is less likely to happen.
Is it necessary to break in a barrel?
A barrel may not always need to be broken in, and some may be more difficult. This process is commonly brought up with precision shooters and when things are not working properly with a new barrel. It is important to break in a barrel anytime you would need to have as much accuracy as possible such as competitions and hunting. Of course you always want an accurate barrel, however in these types of scenarios you would want to eliminate as much variability as possible to create a smooth, even surface in the barrel.
How to break in a barrel
The process of breaking in a barrel is rather simple but can be time consuming.
Things you’ll need when you head to the range to break in your barrel include:
- Appropriate ammunition
- Barrel solvent
- Cleaning rod
- Cleaning patches
- Cleaning kit
- To start, you’ll want to fire a single shot
- Let the barrel cool if needed, then swab the barrel with a barrel solvent. You’ll want to follow the directions on the solvent you use. Generally though, to swab the barrel with barrel solvent, you’ll want to take a few cleaning patches soaked in the solvent and make several passes through the barrel.
- Let the solvent soak in the barrel for about five minutes.
- Push some clean patches through the barrel until they come out clean. Copper will show up as a green-blue color on the patch.
- Fire another shot and repeat this process for 15-20 rounds.
- Do a thorough cleaning with your cleaning kit. For more information on performing a thorough cleaning on your firearm, read our How to Clean and Maintain your AR-15 here.
This is a fairly simple and straightforward process, but take your time. After completing this process approximately 15-20 times, there shouldn’t be anything showing on the patches. Some barrels may be more difficult to break in and after completing several rounds of this process may still show blue-green patches at the end. Keep in mind that you can adapt this process if needed. You can change the number of times you complete the process depending on the barrel. While this process may be long, it does improve the accuracy of the barrel sooner. Invite some friends with you to the range and have fun with it. It will make the time go by quickly.
