Is breaking in the barrel of a new rifle an absolutely essential process? If you line up 10 different shooters and ask them, you probably will get 11 different answers. And, for die-hard shooters, they will be prepared to fight to the death over their answers. This seems to be a hotly contested topic. If you think the 9mm vs. .45 debate gets heated, just start talking about barrel break-in procedures!

Magic!

We all know there’s only one real way to break in a barrel. And that is to wait until there is a full moon the first Monday night after the Winter Solstice at three-and-a-half minutes past midnight on the equator while turning counter-clockwise and hopping on your left foot. You have to rub half a potato against a frog and then toss it (the potato, not the frog) over your left shoulder into a spring-fed pond. You then fire one round through the rifle and clean it using (insert favorite barrel copper solvent here) with precisely seven passes through the barrel with a bronze brush. Then fire another round and repeat. Next, fire two rounds, followed by seven more passes from the bronze brush….

A witch, representing imaginary witchcraft of barrel break-ins. — Honestly, there’s no witchcraft or sorcery involved. No magical solutions that unlock the Key To Accuracy. Photo by BBC.

Okay, it sounds ridiculous, doesn’t it? But honestly, I’ve talked with people who are absolutely, positively convinced that unless you engage in a lengthy, complex process that takes many hours and possibly a few shooting sessions at the range, your rifle will not shoot worth a damn. Trying to convince them otherwise is one of the most fruitless endeavors you’ll ever try to undertake.

Some folks advocate firing a single round and then thoroughly cleaning the barrel. Fire two rounds, then clean the barrel again. Fire three rounds, then clean the barrel — all the way up through 20 rounds. I’ve never tried that, but some swear by it, claiming it makes their rifles more accurate when they are new.

Barrels

Here’s the thing: every single barrel out there is a bit different and unique. You can take a bunch of rifles from the same manufacturer, the same exact type of rifle, and get different results. Now, it’s reasonable to expect that each of them will shoot similarly, and good companies that have solid quality control will turn out rifles that perform to a certain level. But even then, you’ll likely find a few rifles in that batch that just seem to shoot extra-tight groups.

The muzzle from a Ruger American Predator Rifle. — Not all barrels are created equal. Each one has its nuances. Even the same model rifles will have tiny differences in their barrels. Photo by Jim Davis.

Occasionally, a rifle slips through that just doesn’t perform. The inside of the barrel will look just like all the rest, but for some unknown reason, it just won’t be very accurate. There’s no accounting for it.

Levels Of Quality

There are a couple of levels of quality out there for barrels these days.

We have mass-produced barrels, which can vary the most in quality. They usually have no post-production lapping of the rifling, and the inside of the barrel can have a lot of machine marks. Sometimes, the reamers can be worn or misaligned, which can degrade accuracy.

Ruger American Predator. — This Ruger American Predator is a stock factory rifle but exhibits uncanny accuracy, especially for a production rifle. Photo by Jim Davis.

Custom rifle makers normally take more time and check the finished product carefully. They often lap the barrel, which polishes the rifling, and that usually helps accuracy because the bullet can mate better with the rifling.

Fallacies

Because every barrel from every rifle produced is a little different, it is absolutely impossible to say that if a given barrel was given a break-in, it would shoot any better than it now does. To say such a thing, we’d have to have two precisely identical barrels and then administer the break-in for one while leaving the other without a break-in. And we can’t do that because there’s no such thing as two identical barrels.

To claim anything else would be a fallacy. You can’t tell me, “Gosh, your barrel would have been more accurate had you taken the time to do my magic, secret break-in procedure” because you have no other yardstick to go by. You simply don’t know.

Natural Break-In

As we put some rounds down range, the bullets have a sort of polishing effect on the barrel, sort of like lapping. It naturally wears in the barrel, and this can have a positive effect on accuracy. Those tooling marks can get worn in, too. Mind you, while this is happening, though, fouling of the barrel is taking place as deposits of carbon, lead, and/or copper are being left behind.

Practical Results

Having served a couple of years on a law enforcement sniper team, I’ve shot with a substantial number of precision shooters, not only from my agency but from several others. Quite a few of them had rituals for breaking in their respective barrels.

Some would use lapping compound, which was intended to polish the rifling as mentioned above. Most swore that this was the magic secret to true accuracy. Did it hurt anything? I would imagine not. Did it help, and was it that magic pill that unlocked the secrets of accuracy? Who’s to know? But each one of them believed that it was, and I guess that made it work for them.

I have to say, though, that most of us (and our respective rifles) exhibited very similar accuracy results overall. Whether we lapped our rifles or not didn’t seem to make much difference.

As a side note, in those days, the vast majority of shooters, including the FBI snipers that we worked with, used the Remington 700 in .308 in one form or another.

Inevitable

One thing is for sure: a barrel is going to change as it is used, regardless of whether we conduct special rituals or not. Simply by sending rounds down the barrel, it’s going to change. With a production barrel that exhibits tool marks, it can take 100-200 rounds before the barrel is broken in and stabilized. As this happens, shot groups can tighten up.

As our round count goes up, accuracy can also eventually begin to degrade as the barrel’s rifling wears. Typically, this is after several thousand rounds (often in excess of 10,000 rounds, depending on caliber).

Cleaning Is Important!

One thing that I can tell you, beyond the shadow of a doubt, is that cleaning the barrel is important. That’s a fact, not my opinion.

As snipers, we were taught to clean the rifle barrels of our sniper rifles at least every 20 rounds, if not more frequently, to maintain accuracy. The more often we cleaned the barrels, the better accuracy remained. If we slacked off on cleaning, then our groups opened up considerably. This applied more so to the bolt action precision rifles we used.

The author at one of the sniper schools he attended. — During sniper school, students were taught to regularly clean the bore of their weapons to keep shot groups tight. For sniper rifles, that meant about every 20 rounds. Photo: Author’s collection.

This was because fouling began to build up in the rifling, so the bullet couldn’t grip the rifling as well as if it were cleaned. Clean rifling allows the bullet to mate with it more efficiently.

The copper on the bullet jacket tends to rub off on the rifling, which causes fouling. That copper builds up on the rifling.

Bullet velocity is important in this regard, in that the higher velocity bullets deposit more fouling, more quickly.

Bullet hardness also matters; the harder the bullet, the less give that it has, and the more copper it will leave behind. A lead core bullet with a thin copper jacket will leave less copper behind. A solid copper bullet or an armor-piercing bullet will leave behind more copper because they are more rigid.

We still cleaned our semi-autos (AR-15 A2 Colt HBARs), but not quite as frequently. They weren’t our precision rifles and were used for a higher volume of fire. Cleaning them every 20 rounds would have been impractical.

Solvents

It’s important to use a good solvent that will get rid of the copper fouling in the bore. I like Shooter’s Choice solvents and have also used Sweet’s 7.62 with good effect.

A cleaning patch emerges dirty from this barrel. — Regular cleaning is an absolute must. As a rule with precision rifles, no more than 20 rounds should be fired between cleanings. A quality solvent will remove fouling, including copper, from the bore. Keep running patches through until they come out clean. Photo by Outdoor Life.

Run a solvent-soaked patch through the barrel (or several), and let it soak for a few minutes. Run a brush through the barrel several times and then another solvent-soaked patch. The patches will have green on them, which is the copper coming out of the rifling. Run some dry patches through the barrel until they come out clean. It may take a little while.

If the green still keeps coming out for a while, don’t be afraid to run a few more wet patches through the barrel and then more dry patches until they are clean. Alternate this process until the patches come out spotless.

Frequent cleaning will make it easier. The longer you let it go, the tougher it is to get the fouling out of the bore.

Parting Shots

Whether or not a barrel break-in procedure is effective is anyone’s guess. If it makes you feel better, then by all means, soldier on with it.

Proper cleaning leads to increased accuracy. And that cleaning has to be thorough and frequent. Use quality solvents and cleaning gear for the job. There’s no sorcery or witchcraft involved. Just good, old-fashioned cleaning. Hey, has anyone seen my lucky rabbit’s foot? I put it here on the table and now it’s gone…

How about our readers – what’s your take on a barrel break-in process? Do you swear by it or at it?