Let’s face it, getting a new rifle doesn’t happen very often. So when you finally decide on the rifle and caliber of your choice, a few simple steps should be taken to ensure you and your rifle will have many great years together. Some people might say you don’t need to break in a new rifle barrel and others will say it’s a must do procedure. My opinion, it can’t hurt to break in a new barrel. I'm also reminded of a quote from Col. Townsend Whelen, "Only accurate rifles are interesting." That furthers my drive to ensure I do what I can to have a repeatable rifle.
I’ve read a lot of things on this subject (mostly during the random years when I decide to pick up a new gun) and it seems that most people will agree that a rifle break-in period is a good thing. Each time you do this, understand that this isn’t a hurry up and shoot several rounds and call it good. If I’m breaking in a new rifle barrel, I like to get to my shooting area very early in the morning and prepare for at least 25-30 shots and possibly five hours of your time.
Basically, the process of breaking in a new barrel is essentially just conditioning the barrel to smooth everything out (remove small burrs). Some barrel materials may take more rounds, others might not need much at all. Keep in mind that you don't want to burn your barrel up in this process. Rifle barrels don't last forever, so like I mention at the end of this article, if your rifle shoots great using half the steps, then call it good.
After getting set up at your shooting location, take one shot and then go through your preferred method for cleaning a rifle barrel.
You don’t need a thorough deep clean here, but you can follow a simple process for cleaning your rifle barrel here. At this stage, don’t really worry about where you’re hitting. I like to place a target at close range for this process, just for something to aim at. But, to save some time while this barrel break-in process is going on, I’ll also make some small adjustments to my scope so I’m hitting paper.
Repeat step one for the first 10 shots through your barrel. This process will take you a while because you’re cleaning your rifle between each shot. Also, cleaning your rifle between each shot allows for your barrel to cool down. Depending on the size of your barrel, the cooling time can vary. I like to wait at least 5 to 10 minutes, but sometimes I will wait a full 20 minutes for a true cold bore shot (a true cold bore shot isn't really needed in this stage).
Next, shoot a three round group and then clean your barrel. Again, don’t really worry where your bullets are hitting.
You will do this step for a total of fifteen rounds, so you will repeat the three shot and clean for a total of five sessions.
Finally, you’ll want to shoot five rounds and then clean your barrel. After you’ve cleaned the barrel, you’ll want to take a foul shot.
Now you can shoot three rounds to test for accuracy if you want, or call it day. From here on out, your rifle is now ready to handle anything you throw at it.
Let’s say you take out a new rifle and shoot your first few rounds through the barrel and your shots are all sub or MOA accurate. You take several more shot and they are still grouping perfectly. In this situation, you can probably just stop right there. Every barrel has different life expectancies, so after figuring out that your new rifle shoots great, it might be best to spend the rest of your time at a later date testing loads and sighting in your rifle.
Here's a summary of the steps:
People might be on the fence if a barrel break-in process is necessary, but I lean toward to side of caution and will gladly spend the time to slowly shoot a new rifle that I want to get plenty years out of.
Take one shot. Clean the barrel.
Shoot a 3 shot group. Clean the barrel.
Shoot five rounds. Clean the barrel.
Shoot three rounds for accuracy.
Repeat for 10 shots.
Repeat for 15 shots.
Take a foul shot.