Do You Really Need to Break in a New Rifle Barrel?
BY Herschel Smith
2 years, 2 months ago
You just bought a new rifle—or maybe had a new barrel installed on an old gun—and are about to head to the range. As much as you want to put a bunch of rounds through it, there’s a little voice in your ear urging caution: Be sure to break in the barrel first!
Chances are you’ve heard this warning from the guy behind the gun counter, or your buddy who’s a ballistic know-it-all, or perhaps from the maker of the barrel or rifle itself—they often include instructions on barrel break-in.
Yep. I have.
When I was first introduced to the concept some decades ago, the explanation given to me was that the first shots through a barrel would smooth out imperfections in the bore left by the tooling that was used to cut the chamber and impart the rifling in the bore. But you also needed to clean the barrel frequently to begin with so that fouling wouldn’t accumulate too thickly on some of these bumps leading to worse problems down the line. If a smear of copper was allowed to form on one of these rough spots and grow, it would degrade accuracy and would be difficult to remove once it established itself—so the story goes.
I know that’s the alleged problem. I don’t believe it. Copper will only foul so far until it gets beaten down and worn off by bullets. Besides, copper needs to fill in the microcracks and grain boundaries in the metal. That’s why I’ve stopped cleaning bores with a wire brush and favor polymer brushes now. I see no need for anything else.
I’ve had many conversations with barrel makers about the break-in procedures they publish and most of them have confessed that the only reason they have a break-in process is because their customers think they need one. Wade Hull at Shilen has come right out and said as much. The general shooter is convinced that a break-in procedure is needed, so the barrel makers have responded by creating them—even if they don’t believe they are necessary.
Third, I’ve tried all these techniques over the years, and I’d be lying if I told you I ever saw a measurable benefit.
Exactly. As you can tell, I don’t believe in barrel break-in procedures. I’ve done it before. I don’t do it anymore and analogize these procedures to superstition.
If you disagree or you can point to actual data that proves otherwise, drop a note in the comments.
On September 6, 2022 at 11:07 pm, George 1 said:
I read a comment by mark LaRue a few years ago concerning barrel break in procedures for his barrels. He said, ” Just go out and shoot. Don’t do mag dumps or otherwise get the barrel really hot for the first 150 rds or so.”
On September 7, 2022 at 12:02 pm, Ned said:
Years ago in G&A, Ross Seyfried outlined a barrel break-in procedure that sounds just like the ones you hear about nowadays. Said he didn’t do it anymore, because he found no difference in fouling or accuracy with the break-in procedure or without.
On September 7, 2022 at 12:06 pm, Steady Steve said:
I have noticed a slight improvement in accuracy for a new rifle if I first disassemble it, clean it thoroughly, lube it, then shoot 100 rounds through it without letting the barrel get too hot. Another thorough cleaning after this, including using Shooters Choice MC-7 to remove all of the copper fouling. This has worked for me on bolt actions, lever actions, and semi autos.
On September 7, 2022 at 5:47 pm, Joe Blow said:
Reminds me of the debate about using soap to wash cast iron…. lol.
On September 7, 2022 at 8:08 pm, Heywood said:
@George 1
I bought a LaRue several years ago. Called to find out about barrel break in. They looked up my purchase and called some guy to the phone. He was the one who made my gun (they keep track). Anyway I asked him about break in and he said the same thing. “Shoot it, but don’t melt it.” He said they pride themselves on putting out a product that is ready to go right out of the box. I shot a few rounds for fun and then sighted in my Leupold scope. 10 shots total for sight in. Less than 1 MOA. Yep, it was spendy but is the finest shooting AR platform gun I have ever used.
On September 7, 2022 at 9:01 pm, George 1 said:
@heywood
I have just used LaRue barrels for a few of my builds. I have not owned a complete LaRue rifle. A guy I worked with years ago had one. It was a sweet rifle. He reported the same as you, no trouble getting sub MOA groups anytime he wanted with complete reliability.
The rifles I have put together with LaRue barrels will all shoot under MOA with match ammo. With the cheap ammo they are still 1.5 to 1.75 MOA.
On September 8, 2022 at 10:06 am, Heywood said:
@George 1
I didn’t mention. The guy on the phone was really cool. He told me to use match ammo because “if it doesn’t shoot straight, it’s you or the ammo. Buying match will eliminate one of those.” We both laughed…he was a great guy.
On September 8, 2022 at 10:22 am, Latigo Morgan said:
There was a guy on one of the many now defunct gun forums I used to frequent who said he was employed by one of the famous barrel manufacturers.
Some asked him in a post once about barrel break in procedures. His advice then was to just shoot.
I recall he said something along the lines that barrel break ins just reduce barrel life due to the excessive cleanings, which barrel manufacturers love because then they get to sell more barrels.
On September 9, 2022 at 3:12 pm, R.B. Phillips said:
I’ve never found anything changing after “break-in” except that for some production rifles, the barrels clean faster after 700 rounds or thereabouts (1990s Remington). Zero difference in velocity or accuracy.
On September 9, 2022 at 3:25 pm, Michael R Becker said:
I don’t know much about rifle barrels, but I do know that a 45ACP is by far the most superior round for a self-defense pistol. No other pistol round has the same stopping power.
So there.
On September 9, 2022 at 3:28 pm, denton said:
Only the first shot through a really clean barrel removes imperfections. After that, the imperfections just pile up layers of copper. Hence, shoot 1 round, clean thoroughly, then shoot another.
I have a wonderful 100 year old milsurp rifle that copper fouled very quickly. After 100 years of “just being shot”, I bought it, cleaned it thoroughly, and then shot 1 round, cleaned, shot another, etc. until I was getting less copper. Then I shot 3, cleaned thoroughly, and shot 3 more. Now it fouls much less, and goes a lot longer between cleanings.
OTOH, I have a 7×57 Zastava barrel that fouled only very slowly and needed no break in.
If you pay attention, your barrel will tell you if it needs break in. Some do, some don’t.
If your cleaning method is damaging your barrel, you are doing it wrong.
On September 9, 2022 at 3:30 pm, Pillage Idiot said:
I have no specific knowledge about barrel break ins.
However, I know lots of excellent shooters that have mentioned that their rifle became much more accurate after X number of rounds down the barrel.
SOMETHING about the process of discharging rounds through the barrel changes the environment encountered by the bullet!
On September 9, 2022 at 3:34 pm, RSR said:
Break-ins are really dependent on the type of treatment of the bore. For chrome and nitride, just shoot. For bare chrome moly/carbon or stainless untreated, there can be some benefit.
But primarily, I think break-ins were geared towards competitive precision shooters who were looking for that sweet spot of worn in consistency between new and “worn out” to max mechanical accuracy potential without incurring the erosion or cost of firing rounds — these are the same folks who say a barrel is “worn out” from a few hundred to few thousands of rounds depending on caliber, while hunters or military would find acceptable accuracy for 5 to 10 times as long.
Modern manufacturing and increased precision there, as well as better QC, has also done a lot to eliminate the need for barrel break-ins — used to be precision crowd would junk a fair share of barrels after break in if they didn’t meet accuracy standards. Now that’s really just a problem w/ cheapo AR barrels AFAIK.
So that’s why break-ins are generally doing more harm than good nowadays — just for starters, how many of the folks breaking guns in are doing so from the chamber and with single piece cleaning rods; hence, damage to crown from the barrel’s start and a reduction in accuracy for barrel’s lifetime unless it’s recrowned…
On September 9, 2022 at 4:07 pm, =TW= said:
New barrels: clean bore, then apply gun oil. Dry patch before shooting.
Adjust sights and test for function, loose mounts etc. I prefer jacketed bullets for this. Best not to overheat the weapon- 20-50 rds. should suffice. Clean as above.
Repeat next range day.
After that, feel free to bang away.
On September 9, 2022 at 4:11 pm, Eric said:
I’ve shot a fair number of new guns in my life. Ranging from the Sig P365XL i bought in May this year to the M16A2 the Army issued me in 1986. And the M256A1 120mm smoothbore on the M1A1C that I signed for brand new in the summer of ’91 after Desert Storm. And the M9 pistol that they issued me in 1990 (ugh, please never do that to me again). All in all, I’ve shot at least 25 new guns in my life. This year I’ve added 2 pistols and a rifle, for example.
I have never done a “barrel break-in”. I have never had accuracy issues that weren’t created by me. What I do is disassemble, clean, reassemble, function check, dry fire that new gun every day from the day I take it home until I go to the range. That’s generally within the week, since I tend to shoot on Sundays. First day at the range, I zero it and then put 100 rounds, give or take, through the gun. I take it home and do the disassemble, clean, reassemble, etc process. The gun is good to go at that point.
That tank main gun shot perfectly the first round we put through it :-)
On September 9, 2022 at 7:12 pm, Russell G. said:
Breaking in is B.S. That is, the fire, scrub, fire, scrub, repeat repeat etc.
If you’re worried about the lands and grooves having metal frags, you can run a mop down it with Blue Coral several times in a new bore…Notice what comes out while you are patching the Blue Coral out (with kerosene). If a barrel has been air gapped, then…well, you get it.
The best thing to do is clean and oil a new barrel before you hit the range. (And bronze brushes don’t remove copper). De-coppering agents remove copper.
And, copper fouling does affect accuracy. No doubt about it from my range cards. Set your chrono up and start firing away. You’ll see when it starts to kick in…the velocity starts increasing significantly off baseline. At longer distances this will affect accuracy, or, you’ll get flyers. Fouling will be faster with older IMR powders and slower with CFE powders and good stuff like Vihtavouri and Norma. Softer bullets like Noslers will foul faster than harder bullets like HDY Vmaxs and SIE MKs.
There is evidence that copper fouling does reach an equilibrium (T. Rex; below discusses that and shows borescope images), but…meh, why deal with it as a variable that affects the internal ballistics?
A lot of this relates to Benchrest shooters vs. LDS. Meaning dudes that shoot a lot of rounds at a setting vs dudes that don’t shoot a lot of rounds and have a standard load that they go long with fewer rounds. T. Rex on the Utubes went over this a long time ago in his sniper 101 series ( https://youtu.be/pwG-D0HjCBQ ) if you want to study/understand the chemical, thermal, and fouling effects on the bore.
On September 9, 2022 at 7:41 pm, Bill B said:
Barrel break-in is a three-step process.
1. Take the new rifle/rebarreled rifle to the range.
2. Sight it in.
3. Take it home and clean it as you normally would.
Barrel break-in complete.
On September 11, 2022 at 12:53 pm, Oklahoma Safe Shooting said:
As a retired Gunsmith of 44 years I can only say that everything I have read here is the very reason I never had to advertise and kept busy all those years. Every single Pro shooter keeps a D.O.P.E. log that includes every single round shot through a barrel. Quality barrels especially tuned ones are broken in to keep the quality in the barrel. Of course use polymer brushes but only pulled from breach to muzzle and never dipped into the bottle of cleaner unless you just want to contaminate it on purpose.
Possibly the thinking in this disposable society is if it won’t shoot well then just get another one that will. All I can say is repeatably at 1000 yards doesn’t happen by accident or by just shooting your barrel. I know many won’t like my comments but exactly how many thousands of rifles have you worked on?
On September 11, 2022 at 7:17 pm, Herschel Smith said:
@Oklahom Safe Shooting,
“I know many won’t like my comments but exactly how many thousands of rifles have you worked on?”
Maybe you don’t understand. I open it up and ask for comments because it’s a good thing to learn from experience.
Next, I don’t understand what you’re saying. You’re advocating a break-in, as best as I can determine, but you supply no procedure.
Next, you agree with polymer brushes, pulled from breach to muzzle as would make sense to anyone, but then … disagree with use of solvents, or something, I can’t tell.
You need to supply more detail for your comment to make any sense to the rest of us.
On September 12, 2022 at 2:16 pm, Oklahoma Safe Shooting said:
Thanks for asking and I would be more than happy to answer. First and foremost a barrel is made from tempered steel or in some cases a chrome liner in a lighter barrel shroud. Lets just look at the normal barrel. First off people assume that a brass brush can’t damage a steel barrel. The thinking is the brush can’t scratch the barrel or lands and that is true, BUT the brush is brass, a soft metal, and can leave deposits in the lands, grooves and pores of the metal just like copper from a bullet can. Using a polymer brush removes that problem. All you are trying to accomplish with the brush is removal of loose particles left in the barrel from shooting. As to bore cleaner I said not to dip your dirty brush in the cleaner because you will contaminate the whole bottle and from then on you will be transferring what you removed back into the barrel. As to how to brush or use a jag with a patch it should always be from breach to end of barrel and never the other way around. Think of it like this if you take your tooth brush that’s wet with toothpaste as well and stroke your finger across the end of the bristles do you see all the material that flies off the bristles as you do that? The same thing happens when you pass a brush from muzzle to breach; all that residue is now coating the walls of the chamber and locking lugs and will require extra cleaning to remove. A barrel should always be cleaned from breach to muzzle the same way the bullet travels.
Next after one or possible two passes from the brush should be a patch that has clean bore solvent applied. Pull through slowly to allow the solvent to coat the barrel as you pull. Now leave the barrel alone for about 5 minutes and allow the solvent to do its job. Too many think the brush is doing all the work “scrubbing” the barrel. Many will push back and forth up to ten times before they ever remove the brush. All you have accomplished by this action is much more work for yourself and the need to purchase another brush. After waiting pull a dry patch through the barrel. Solvents are designed to react with burned powder as well as copper and lead fouling. If you are using a solvent designed for copper fouling you will notice a bluish-green color of the patch when it comes out of the barrel this color is an indication to you that the solvent has worked with the copper and is indeed being removed. Perhaps a second or third patch will be required to remove all the debris. Use a good quality light to inspect the barrel and look for deposits still remaining and if necessary repeat the first steps until clean. Next using another patch apply oil or FrogLube and again pull the patch through slowly; you want to protect the barrel until its next use. Finally pull another clean patch through to remove any excess lubricant. The last thing you want is lubricant slowly coming down the barrel and into the action while in storage.
A couple of notes here are necessary. You will note I was constantly using the phrase of pulling through a barrel. This is because for the most part and exclusively for field cleaning I use the Otis cleaning system. The military has adopted this as well as the normal screw together rod and brush system. Also those familiar with the military system also know about the breach brush. This particular brush used for the AR/M4 platform features a chamber and locking bolt bristles. It is not designed to be pushed through the barrel. If you are using the screw together rod system then it is always pushed from breach to muzzle and then the brush or patch is removed before the rod is withdrawn. Of note for AR platform shooters is the gas port in the barrel. Please remember this area always shaves off micro-particles of copper so from time to time a deep cleaning is required and removal of the gas tube and cleaning it again from breach end to barrel end; it easier to remove debris in this manner.
Now lastly do I advocate breaking in a barrel…..absolutely. It only takes 10 rounds and a bit of your time. Shoot a round; clean as above. Shoot the next round and repeat cleaning. Shoot the third round and clean again. Repeat this process for all 10 rounds and you are done with break in. You will also start seeing a change about the 7th or 8th round where it has far less fouling left after the shot. This is because you have not overheated the barrel and instead of fouling filling the pores of the metal the lubricant has taken its place. You may have noted my mention of FrogLube and that is because I have used it for over 10 years now. I can prove with a borescope the effect it has on a firearm and the lack of fouling left behind of a firearm that has been properly treated with FrogLube.
As I said my intent was not to anger anyone with my posting but only give my observations as a gunsmith of 44 years.
On September 12, 2022 at 2:31 pm, Herschel Smith said:
@Oklahoma Safe Shooting,
I think most people follow your advice concerning cleaning.
As for breaking the barrel in, that was the main point. There are those who disagree with you, but thanks for the viewpoint.