Rifle Barrel Break-In:
Author: Gale McMillan, of McMillan Stocks
Gale McMillan, of McMillan Stocks fame, was one of the finest barrel-makers and benchrest shooters of all time. Here he argues that elaborate barrel break-in procedures do more harm than good.
As a barrel maker I have looked in thousands of new and used barrels with a bore scope and I will tell you that if every one followed the prescribed [one shot, one clean] break-in method, a very large number would do more harm than good. The reason you hear of the gain in accuracy is because if you chamber a barrel with a reamer that has a dull throater instead of cutting clean sharp rifling it smears a burr up on the down wind side of the rifling. It takes from one to two hundred rounds to burn this burr out and the rifle to settle down and shoot its best. Any one who chambers rifle barrels has tolerances on how dull to let the reamer get and factories let them go longer than any competent smith would.
Another tidbit to consider--take a 300 Win Mag that has a life expectancy of 1000 rounds. Use 10% of it up with your break-in procedure. For every 10 barrels the barrel-maker makes he has to make one more just to take care of the break-in. No wonder barrel-makers like to see this. Now when you flame me on this please [explain] what you think is happening to the inside of your barrel during the break in that is helping you.
Consider this: every round shot in breaking-in a barrel is one round off the life of said rifle barrel. No one has ever told me the physical reason of what happens during break-in firing. In other words what, to the number of pounds of powder shot at any given pressure, is the life of the barrel. No one has ever explained what is being accomplished by shooting and cleaning in any prescribed method. Start your barrel off with 5 rounds and clean it thoroughly and do it again. Nev Maden, a friend down under that my brother taught to make barrels was the one who came up with the [one shot one clean] break-in method. He may think he has come upon something, or he has come up with another way to sell barrels. I feel that the first shot out of a barrel is its best and every one after that deteriorates [the bore] until the barrel is gone. If some one can explain what physically takes place during break-in to modify the barrel then I may change my mind. As the physical properties of a barrel don't change because of the break-in procedures it means it's all hog wash. I am open to any suggestions that can be documented otherwise if it is just someone's opinion--forget it.
It all got started when a barrel maker that I know started putting break-in instructions in the box with each barrel he shipped a few years ago. I asked him how he figured it would help and his reply was if they shoot 100 rounds breaking in this barrel that's total life is 3000 rounds and I make 1000 barrels a year just figure how many more barrels I will get to make. He had a point; it definitely will shorten the barrel life. I have been a barrel maker a fair amount of time and my barrels have set and reset benchrest world records so many times I quit keeping track (at one time they held 7 at one time) along with High Power, Silhouette, Small bore national and world records and my instructions were to clean as often as possible preferably every 10 rounds. I inspect every barrel taken off and every new barrel before it is shipped with a bore scope and I will tell you all that I see far more barrels ruined by cleaning rods than I see worn out from normal wear and tear. I am even reading about people recommending breaking-in pistols. As if it will help their shooting ability or the guns.
Gale also covers the topic at Snipercountry
To achieve the best results for accuracy you should clean the chamber and bore after every round for the first 25 rounds and then every 10 rounds up to 100 rounds. It usually takes about 200 rounds per barrel for optimum accuracy
I've spent the last few months trying to get a better understanding of what a barrel break-in process is and how to properly clean a rifle. What to do and what not to do.
I've spent a lot of time on this board, the BR board and other shooting boards listening to members and what works for them. Conclusion, what works for some, doesn't work for others. Being an engineer in the telecommunications field, when it's broke or you don't understand something you go back to manufactures specs and schematics. So that's kind of what I did on this subject.
I've talked with 4 metallurgist and 3 barrel manufactures (Rock Creek, Hart and Shilen), on the subject. From a scientific point of view, they all said and agreed to pretty much the same thing.
First, barrel break-in processes keep them in business. This shoot and clean, shoot and clean every round or few rounds break-in process only damages your brand new match barrel. Think of a car engine for a moment. Why do we use oil in the engine? To prevent metal-to-metal contact and reduce friction between two metal surfaces. Your barrel is no different from the engine. Mike Rock at Rock Creek barrels gave me the most detailed explanations on barrels and ballistics. Mike has his degree in metallurgy; he was also the chief ballistics engineer for the Army for many years at the Aberdeen Proving grounds. Stan Rivenbark was one of the top ballistic engineers for Raytheon before he retired in the 70's and also has a degree in metallurgy. I also talked with two local metallurgists here in North TX. I confirmed my findings with each person to see if they agreed or disagreed. Conclusion, they all agreed with each other's assessments.
When Mike worked at Aberdeen proving grounds, the Army used high speed bore videos with mirrors, thermal imaging and computers to analyze any and everything that happens when the firing pin hits the primer and the round goes off. When the primer ignites there is enough pressure to move the bullet forward into the lands. The bullet then stops. As the primer ignites the powder, more pressure builds moving the bullet forward where it can stop again. Once there is enough pressure from the round going off, the bullet is moved down out the barrel. All of this happens in nanoseconds (billionths of a second). Your bullet starts and stops at least twice and sometimes three times before it leaves the barrel. This is fact.
If you clean every round or every few rounds during your barrel break-in process or clean your rifle so well after shooting that you take it down to the bare metal, you've created a metal-to-metal contact surface for the next time you shoot the gun. So what's the problem with this you ask? Just like your car engine, metal-to-metal contact will sheer away layers of metal from each surface. So if your bullet is starting and stopping two or three times as it leaves the barrel, that's two or three places for metal-to-metal contact to happen as well as the rest of your bore. The use of JB's and Flitz can and will take you down to metal-to-metal contact. For all intents and purposes, JB's and Flitz are not the most ideal products for cleaning your rifle.
According to Mike Rock, and the other barrel manufactures agreed, all you need to avoid this metal-to-metal contact is a good burnish in the barrel. Shilen, Hart and Rock Creek will all void your barrel warranty if you shoot moly bullets and for good reason. This is not to say that moly is necessarily bad for a barrel, but it is when applied to bullets. There is no way possible to coat a bore with moly bullets. The bullet contact surface in the barrel is only so big. But when your round goes off, moly comes off the contact surface of the bullet in the throat area of the rifle and is bonded to the barrel due to the excessive heat and pressure. We're not talking coated or adhered to, we're talking bonded, d**n near permanent. With this, some of the jacket coating comes off the bullet. Follow this up with another round and you've now embedded the copper jacket between layers of bonded moly. This is the beginning of the black moly ring, which ruins countless barrels and is so hard; it can hardly be scraped off with a screwdriver's corner edge. This is what happened to a new Shilen SS select match barrel I had to have replaced with less than 400 rounds through it. I can't talk for Fastex as I don't or none of the folks I talked to knew enough about the product to comment on it. When I talked to Mike about my new barrel and the barrel break-in process, this is what he had to say. He first hand laps each barrel with a lead lap. He then uses two products from Sentry Solutions, a product called Smooth Coat, which is an alcohol and moly based product. He applies wet patches of Smooth Coats until the bore is good and saturated and lets it sit until the alcohol evaporates. The barrel now has loose moly in it. Next he uses a product called BP-2000, which is a very fine moly powder. Applied to a patch wrapped around a bore brush, he makes a hundred passes or so through the barrel very rapidly before having to rest. He repeats this process with fresh patches containing the moly powder a few more times. What he is doing is burnishing the barrel surface with moly and filling in any fine micro lines left by the hand lapping. He then uses a couple of clean patches to knock out any remaining moly left in the bore.
With the barrel burnished with moly, this will prevent any metal-to-metal contact during the barrel break-in process. My instructions for barrel break-in were quite simple. Shoot 20 rounds (non-moly bullets) with no cleaning, as this will further burnish the barrel. Done! Now shoot and clean using your regular regimen of cleaning and if you have to use JB's or flitz type products, go very easy with them, or better yet avoid them. Never clean down to bare metal. He said most of the cleaning products do a great job, don't be afraid to use a brush and go easy on the ammonia-based products for removing copper fouling. Basically don't let the ammonia-based products remain in the barrel for long lengths of time.
Well that's the long and skinny from the scientific point of view on the subject. If you're ever in doubt about the real condition of your barrel, take it to someone who has a bore scope and even better if someone has a bore scope that can magnify the view. You may be surprised at what is really going on in your barrel.
With any premium barrel that has been finish lapped (such as a Krieger Barrel), the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.
Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is released into the gas which at this temperature and pressure is actually a plasma. This copper dust is vaporized in the gas and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore, when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it; copper which adheres well to itself, will build up quickly and may become difficult to remove. So . . . when we break in a barrel, our goal is to get the throat polished without allowing copper to build up in the bore. This is the reason for the "fire-one-shot-and-clean" procedure.
Each barrel will vary slightly as to how many rounds it will take to break in. This is because of things like machinability of the steel, steel chemistry, or the condition of the chambering reamer. For example a chrome moly barrel may take longer to break in than stainless steel, because it is more abrasion resistant, even though it might be the same hardness. Also, copper will stick to chrome moly better than stainless steel, so it will usually show a little more color if you are using a chemical cleaner. Rimfire barrels can take an extremely long time to break in . . . sometimes requiring several hundred rounds or more. But, cleaning intervals can be extended to every 25-50 rounds. The break-in procedure procedures are really the same except for the frequency of the cleanings. Remember the goal is to get or keep the barrel clean while polishing out the throat.
The best way to break-in a new barrel is to observe when the fouling becomes reduced. This is better than believing that there is a set number of "shoot and clean" cycles. Many customers report almost no fouling after the first few shots, and more break-in would be pointless. Conversely, if more "shoot and clean" cycles are required, a set number would not solve that problem either. Besides, this break-in procedure is not a completely harmless operation, so it should be done carefully and no more than necessary.
There is no hard and fast rule about barrel break-in procedure, and this is only meant to be a guide to "break-in" based on our experience. Some barrel conditions (chamber, bullet, primer, powder, pressure, velocity etc.) may require more shoot-and-clean cycles than others. It is a good idea to just observe what the barrel is telling you with its fouling pattern. Once your barrel is broken in, there is no need to continue breaking it in.
You should Initially perform the shoot-one-shot-and-clean cycle five times. If copper fouling isn't reduced, fire one shot (5 more times) and so on until fouling begins to drop off. At that point shoot three shots before cleaning and observe. If fouling is reduced, fire five shots before cleaning.
Stainless Chrome moly Barrels
- Fire one shot, then clean your barrel. (Repeat this step 5 to 25 times.)
- Fire three shots, then clean your barrel. (Repeat this step 1 or 2 times.)
- Fire five shots, then clean your barrel and you're done.
Stainless Steel Barrels
-
Fire one shot, then clean your barrel. (Repeat this step 5 times.)
- Fire three shots, then clean your barrel.
- Fire five shots, then clean your barrel and you're done.
With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.
Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this gas and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it; copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat polished without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.
Barrels will vary slightly in how many rounds they take to break in because of things like slightly different machinability of the steel, or steel chemistry, or the condition of the chambering reamer, etc. . . For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is the same hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more color if you are using a chemical cleaner. (Chrome moly and stainless steel are different materials with some things in common and others different.) Rim Fire barrels can take an extremely long time to break in -- sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the clearing procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while polishing out the throat.
Finally, the best way to break-in the barrel is to observe when the barrel is broken in; i.e. when the fouling is reduced. This is better than some set number of cycles of "shoot and clean" as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary.
CLEANING
This section on cleaning is not intended to be a detailed instruction, but rather to point out a few "do's and don'ts". Instructions furnished with bore cleaners, equipment, etc. should be followed unless they would conflict with these "do's and don'ts."
You should use a good quality straight cleaning rod with a freely rotating handle and a rod guide that fits both your receiver raceway and the rod snugly. How straight and how snug? The object is to make sure the rod cannot touch the bore. With service rifle barrels a good rod and guide set-up is especially important as all the cleaning must be done from the muzzle and even slight damage to the barrel crown is extremely detrimental to accuracy.
There are two basic types of bore cleaners -- chemical and abrasive. The chemical cleaners are usually a blend of various ingredients including oils and ammonia that attack the copper. The abrasive cleaners generally contain no chemicals and are an oil, wax, or grease base with an extremely fine abrasive such as chalk, clay, or gypsum. They clean by mechanically removing the fouling. Both are good, and we feel that neither will damage the bore when used properly.
So what is the proper way to use them? First, not all chemical cleaners are compatible with each other. Some, when used together at a certain temperature, can cause severe pitting of the barrel -- even stainless steel barrels. It is fine to use two different cleaners as long as you completely remove the first cleaner from the barrel before cleaning with the second. And, of course, never mix them in the same bottle.
Follow instructions on the bottle as far as soak time, etc. . . Always clean from the breech whenever possible, pushing the patch or swab up to the muzzle and then back without completely exiting the muzzle. If you exit the muzzle, the rod is going to touch the bore and be dragged back in across the crown followed by the patch or brush. Try to avoid dragging things in and out of the muzzle. It will eventually cause uneven wear of the crown. Accuracy will suffer and this can lead you to believe the barrel is shot out, when in fact, it still may have a lot of serviceable life left. A barrel with a worn or damaged crown can be re-crowned and accuracy will usually return.
The chemical cleaners may be the best way to clean service rifle barrels that must be cleaned from the muzzle -- i.e. M1 Garand, M14, etc. . .-- because this method avoids all the scrubbing necessary with the abrasive cleaners and the danger of damaging the crown. But again, as long as the rod doesn't touch the crown, abrasive cleaners should be fine.
Abrasive cleaners work very well. They do not damage the bore, they clean all types of fouling (copper powder, lead, plastic), and they have the added advantage of polishing the throat both in "break in" and later on when the throat begins to roughen again from the rounds fired. One national champion we know polishes the throats on his rifles every several hundred rounds or so with diamond paste to extend their accuracy life.
Again, as with the chemical cleaners, a good rod and rod guide is necessary. A jag with a patch wrapped around it works well. Apply the cleaner and begin scrubbing in short, rather fast strokes of about two to four inches in length. Concentrate most of the strokes in the throat area decreasing the number as you go toward the muzzle. Make a few full-length passes while avoiding exiting the muzzle completely, but do partially exit for about six strokes. You can avoid accidentally exiting by mounting the rifle in a vise or holder of some sort and blocking the rod at the muzzle with the wall or something to keep it from completely exiting.
This sheet is intended to touch on the critical areas of break-in and cleaning and is not intended as a complete, step-by-step guide or recommendation of any product.
The following is a guide to "break-in" based on our experience. This is not a hard and fast rule, only a guide. Some barrel, chamber, bullet, primer, powder, pressure, velocity etc. combinations may require more cycles some less!
It is a good idea to just observe what the barrel is telling you with its fouling pattern. But once it is broken in, there is no need to continue breaking it in.
Initially you should perform the shoot-one-shot-and-clean cycle for five cycles. If fouling hasn't reduced, fire five more cycles and so on until fouling begins to drop off. At that point shoot three shots before cleaning and observe. If fouling is reduced, fire five shots before cleaning. It is interesting to shoot groups during the three and five shot cycles.
| Stainless |
Chrome moly |
| 5 one-shot cycles |
5 - 25 - one-shot cycles |
| 1 three-shot cycle |
2 - three-shot cycles |
| 1 five-shot cycle |
1 - five-shot cycle |
Proper barrel break-in procedures are crucial for top accuracy and performance. More barrels are damaged by cleaning rods than by any amount of regular shooting a person may do. If not done correctly, one can do more harm than good.
The barrel break-in technique we endorse, is the “Speedy Method” named after Speedy Gonzalez, owner of S.G.& Y Rifles. Speedy is well known in Benchrest disciplines; national champion, world record holder, and Hall of Fame inductee in the National Benchrest Shooters Association (NBRSA). He has given permission to share with you, his expert advice on the correct method of barrel break-in and cleaning.
Barrel break-in. Many of our customers upon taking delivery of their new rifle or barrel are in a quandary as how to go about breaking in their rifle for maximum life and accuracy. With so much written in magazines these days stating use this, don’t use that, brush, don’t brush...what’s a person to do?? At S.G.& Y. Rifles, we have a unique opportunity to inspect many rifle barrels on a daily basis with our video borescope. Consequently, we see the results of a variety of barrel break-in and cleaning procedures, and most of them leave the rifle owners with their mouth agape when they see the fruits of their misinformed labor on our color monitor. We have seen practically new barrels ruined with less than a hundred rounds shot through them by some of the crazy and sometimes humorous barrel break-in methods. Anyway here goes for what it’s worth.
A. Bore guides- If you don’t have one, get one! Without a good bore guide you are just wasting your time trying to break-in a barrel or cleaning it for that matter. More rifle barrels are destroyed by cleaning without a bore guide than by shooting! There are many types and brands of bore guides available on the market and range in price from $5.00 to $50.00. The only one we recommend is the Lucas two-piece bore guide. They are the best insurance you can buy for that new barrel. All other bore guides in my opinion are only good for keeping the solvents out of the trigger and action.
B. Solvents - We recommend Sweets 7.62 for copper and a *solvent mix of our own (Actually Pat McMillan gave me this formula) for powder fouling and for cleaning/storing your rifle for the next match or season. This Speedy Formula is made as follows:
Mix 2/3 rds. Hoppes No. 9 Plus Black Powder solvent with 1/3rd. Regular Hoppes No. 9 Nitro solvent. Let this mixture set overnight and it will form a sort of gel that adheres very well to the brush and cuts powder fouling to a minimum.
* Note: Butches Boreshine may be substituted for this Speedy formula.
C. Procedure for “Break-in” - Before firing that first shot, clean the barrel as if it had been shot by following these simple steps.
Step 1. Insert Lucas bore guide into receiver and chamber. If you don’t have one stop here and get one, if not, just shoot your rifle and forget trying to take any care of your barrel at all. If you do have one, proceed, and give yourself one “At-A-Boy” for being astute enough to have purchased the proper tools for the job.
Note: One “Aw-Sh*t” wipes out ALL “At-A-Boys”.
Step 2. Run one wet patch of Sweets through the bore and let soak for approximately 30 seconds. Do not patch this out.
Step 3. Next, run the brush through the barrel only enough to expose the entire brush. Yes, I know that you still have 12 more inches of cleaning rod you could push out the end of your barrel but we want to protect that new crown. Also, if that rod hangs out that far, you will eventually start wearing down the rifling at the crown from about 4 to 7 o’clock. This is very bad “JU-JU” for accuracy. OK, back to our next step. Once the brush is exposed, saturate it well with our Speedy Formula or Butch’s Boreshine and SLOWLY run the brush through the barrel 10 complete back and forth passes while keeping the rod as straight as possible. This is when the Lucas bore guide really pays for itself! Remember, the key word is slowly. We are not trying to break any land speed records today. Let this sit a minute or two and proceed to the next step.
Step 4. After you have let the barrel soak for a few moments, saturate a patch with the Speedy Formula or Butch’s Boreshine and pass it through the bore. Follow this with 2 dry patches and then dry the chamber with Brake Kleen or lighter fluid. Next, gently wipe the crown off with a soft cloth and lube your bolt (lets not gall the lugs just yet). Now, your ready to shoot your first shot. Then follow the schedule below to complete your barrel break-in.
- Clean barrel / lube bolt / 1 shot.
- Clean barrel / lube bolt / 5 shots.
- Clean barrel / lube bolt / 10 shots.
- Clean barrel / lube bolt / 10 to 15 shots and clean again.
D. Additional Barrel Break-in and Cleaning Tips -
1. Each time you clean you may also follow the last dry patch with a patch soaked with LOCK-EEZ. This is a graphite powder suspended in a quick evaporating carrier that coats the bore slightly before passing that first round through a completely dry bore.
2. We are always asked about powder fouling and how to remove it. The only product that we have seen that really does a good job on powder fouling, especially on the carbon ring that forms just ahead of where the neck ends in the chamber, is IOSSO Bore Paste. This is used with a Pro-Shot nylon bristle brush and worked slowly in the neck and throat areas, then slowly down the entire bore. Follow this up with a few wet patches, then dry the bore as usual, and your ready to shoot.
E. Follow the outline above for your regular cleaning program and I promise that your rifle barrels will deliver their greatest accuracy and life without a lot of grief and hours of wondering if they are clean.
Good Shooting,
Speedy Gonzalez
Break-in procedures are as diverse as cleaning techniques. Shilen, Inc. introduced a break-in procedure mostly because customers seemed to think that we should have one. By and large, we don't think breaking-in a new barrel is a big deal. All our stainless steel barrels have been hand lapped as part of their production, as well as any chrome moly barrel we install. Hand lapping a barrel polishes the interior of the barrel and eliminates sharp edges or burrs that could cause jacket deformity. This, in fact, is what you are doing when you break-in a new barrel through firing and cleaning.
Here is our standard recommendation: Clean after each shot for the first 5 shots. The remainder of the break-in is to clean every 5 shots for the next 50 shots. During this time, don't just shoot bullets down the barrel during this 50 shot procedure. This is a great time to begin load development. Zero the scope over the first 5 shots, and start shooting for accuracy with 5-shot groups for the next 50 shots. Same thing applies to fire forming cases for improved or wildcat cartridges. Just firing rounds down a barrel to form brass without any regard to their accuracy is a mistake. It is a waste of time and barrel life.
We recommend that your new Lilja rifle barrel be properly broken-in to obtain the best accuracy. A proper break-in will help ensure that your barrel will clean easily in the future and that you will achieve maximum accuracy potential. Please follow these important instructions.
We are concerned with two types of fouling: copper fouling, which is caused by bullet jacket material being left in the barrel, and powder fouling. During the first few rounds a lot of copper fouling will be left in the barrel. It is important to remove this fouling completely, after each shot, to help prevent a build-up later on. Powder fouling is ongoing, but easy to remove. Do not use moly-coated bullets during the break-in procedure.
For an effective break-in the barrel should be cleaned after every shot for the first 10-12 rounds or until copper fouling stops. Our procedure is to push a cotton patch that is wet with solvent through the barrel. This will remove much of the powder fouling and wet the inside of the barrel with solvent. Next, wet a bronze brush with solvent and stroke the barrel 5-10 times. Follow this by another wet patch and then one dry patch. Now soak the barrel with a strong copper removing solvent until all of the blue mess is removed from the barrel. The copper fouling will be heavy for a few rounds and then taper off quickly in just one or two shots. Once it has stopped or diminished significantly it is time to start shooting 5 shot groups, cleaning after each one. After 25-30 rounds clean at a normal interval of 10-25 rounds. Your barrel is now broken-in.
For a normal cleaning (after a string of 10-25 shots) after break-in, the above procedure should be used, but stop short of soaking the barrel with the strong copper remover. A good rule of thumb is to stroke the barrel with a brush, one cycle for every shot fired.
It is probably a good idea to use a strong copper removing solvent every 200 rounds, or so, to check the barrel for copper fouling. We do not recommend the routine use of abrasive cleaners for normal cleaning. However they can be used every 500-1000 rounds to remove the carbon build-up (caused by powder fouling) in the throat area of the barrel. To use, wrap a cotton patch around a worn out brush or a cleaning jag and liberally apply the abrasive cleaner to the patch. Short stroke the abrasive for 6" or so in the throat area and one or two full length passes through the barrel. Do not clean the barrel like this for more than 1-2 minutes.
It is important to use an action rod guide when cleaning. The guide aligns the rod with the bore and helps prevent uneven wear in the throat area. Be careful not to raise the handle end of the rod while stroking. This will put a "belly" in the rod that will wear the barrel. We suggest that plastic coated rods, like the Dewey and Parker-Hale, be used.
Our preferred cleaning solvent is Butch's Bore Shine made by BBS Industries (406-652-2495). This solvent is excellent at attacking both powder and copper fouling. We recommend it for both break-in and regular cleaning.
For occasional use only, abrasives like J-B paste, Flitz, or RemClean can be used.
Do not use a stainless steel brush in your barrel under any circumstances.
Do not apply a strong copper remover, like Sweets, on a bronze brush. It will ruin the brush and give the false indication that the barrel has copper in it.
For shooters wishing to use moly-coated bullets we do not recommend shooting more than 25 rounds or so without using the normal cleaning procedure outlined above.
To also read Dan's article titled Barrel Fouling - Click Here
BREAK-IN PROCEDURE FOR BARRELS-Jacked bullets
For the first ten shots we recommend, if possible, using jacketed bullets with a nitro powder load. Clean the oil out of the barrel before each shot using something as simple as Windex which will soak the oil out of the pores. After firing each bullet use a good copper cleaner (one with ammonia) to remove the copper fouling from the barrel. We do not recommend anything with an abrasive in it since you are trying to seal the barrel, not keep it agitated.
After cleaning with bore cleaner, clean with Windex after each shot. Use Windex because many bore cleaner use a petroleum base which you want to remove before firing the next shot. This will keep the carbon from building up in the barrel (oil left in the pores, when burned, turns to carbon).
To keep the temperature cool in the barrel, wait at least 5 minutes between break-in shots. The barrel must remain cool during the break-in procedure. If the barrel is allowed to heat up during the break-in, it will destroy the steel's ability to develop a home registration point, or memory. It will have a tendency to make the barrel "walk" when it heats up in the future. I am sure we all have seen barrels that, as they heat up, start to shoot high and then "walk" to the right. This was caused by improperly breaking in the barrel (generally by sitting at a bench rest and shooting 20 rounds in 5 minutes or so). Then, for the rest of the guns life the man complains that barrel is no good. If you take a little time in the beginning and do it right, you will be much more pleased with the barrel in the future.
If you look into the end of the barrel after firing a shot, you will see a light copper-colored wash in the barrel. Remove this before firing the next shot. Somewhere in the procedure, around shot 6 or 7, it will be obvious that the copper color is no longer appearing in the barrel. Continue applications through shot 10.
If you have any ammunitions left, you then may shoot 2 rounds and clean it for the next 10 shots. this is simply insuring that the burnishing process has been completed.
IN theory you are closing the pores of the barrel metal which have been opened and exposed through the cutting and hand lapping procedures.
BREAK-IN PROCEDURE FOR BARRELS-Lead bullets
The same shooting-cleaning process may be used when firing lead bullets and black powder with this exception: shoot 2 bullets, then clean for the first 30 rounds. Naturally, you will use a cleaner appropriate for black powder. You can also use harder lead if available to accelerate the break in. This will accomplish the same as the jacketed bullets.
It may take 80 to 100 rounds to break in with lead. That is why we recommend using jacketed bullets when possible. After this procedure, your barrel's interior surface will be sealed and should shoot cleaner and develop less fouling for the rest of its shooting life.
For best results, of course, it is necessary to 'season' it and use proper cleaning equipment. We like the Dewey coated rods, a good bore guide, copper/bronze brushes and cotton flannel patches, the appropriate size to keep that jag and rod in the middle of the bore. You will need a good bore solvent, like KG 3, Shooters Choice or CR-10 to loosen the fouling, followed by a scrubbing with Holland's Witches Brew or KG 2. After cleaning, nullify the solvents with rubbing alcohol and patch dry. Finish with Tetra Gun Oil, KG 4 or Holland's Bbl Break-in Fluid. Never shoot a dry bore as this will greatly promote copper fouling.
Chris recommends:
Shoot one, clean, for first ten rounds; shoot three, clean, for next thirty rounds; shoot five, clean, while working up load. Allow bbl to cool to the touch before testing a new load to avoid unnecessary throat erosion. It is our desire that your new barrel brings many hours of shooting enjoyment!
NEW BARREL BREAK-IN PROCEDURES
A new barrel will shoot best if careful attention is given to proper break-in. Differing opinions exist, however, we recommend that no more than 20 rounds are fired at the time before cleaning the barrel for the first 60 rounds. Each time the barrel is cleaned for the first 120 rounds, it must be thoroughly cleaned.
Procedure for thorough cleaning: in all cases, it is vital that cleaning tools (brushes, patches, etc.) be pushed from the breech to the muzzle and then removed from the end of the rod at the muzzle end. DO NOT drag anything back through the muzzle.
Clean the bore with a good bore cleaner such as Shooter’s Choice. De-copper the bore with Shooter’s Choice Copper remover or an equivalent.
- Clean the bore with JB Bore Cleaner after 100 rounds as follows:
- 1. Work the JB into the patch.
- 2. Wrap the patch around a worn bronze bore brush (not nylon).
- 3. Using a bore guide, stroke back and forth for 5 strokes in the first half of the barrel. (Breech Half) Push patch through the muzzle and unscrew brush from rod and carefully remove rod from barrel.
- 4. Remove old patch from brush.
- 5. Repeat steps 1 - 5 for 5 complete cycles.
- Note: A neglected barrel my require this to be repeated up for many more cycles until it is smooth.
- Note: The patch will never come out clean as JB is a slightly abrasive compound and is working to polish your throat and bore
CLEANING AND LUBRICATION
After the barrel is broken in, clean the bore immediately each time after the rifle is fired. De-copper the bore and use JB bore cleaner every 300-400 rounds. Field strip and clean the bolt carrier assembly. Use a patch soaked with bore cleaner to clean the bolt carrier bore and the bolt face and stem. Dry all parts and lubricate bolt locking lugs, gas rings, and bolt stem with CLP and reassemble the bolt carrier, lubricating the cam pin and firing pin with CLP during the process. Clean out the inside of the upper receiver with a paper towel or patch; lubricate the charging handle, support rails of the bolt carrier, and the inside of the bolt carrier key. Reassemble.
Note: The entire cleaning process is much easier by bringing a rod, patches, and bore cleaner to the range with you. As soon as you are finished firing the rifle, break the rifle open, remove the bolt carrier assembly, run a little bore cleaner into the two gas vent holes in the dish on the right side of the bolt carrier. Pump the bolt back and forth a few times to distribute the bore cleaner. This will soften the carbon in the bolt carrier and make it very easy to clean once you get home. I also suggest that you run two patches soaked with bore cleaner through the barrel and allow it to soak until you get home and then do a thorough cleaning job.
Proper JB Procedure
This is not an optional procedure if you expect to get maximum life and accuracy out of your premium barrel.
- Clean the bore with JB Bore Cleaner every 2-300 rounds as follows:
- 1. Work the JB into the patch.
- 2. Wrap the patch around a worn bronze bore brush (not nylon).
- 3. Using a bore guide, stroke back and forth for 5 strokes in the first half of the barrel. (Breech Half) Push patch through the muzzle and unscrew brush from rod and carefully remove rod from barrel.
- 4. Remove old patch from brush.
- 5. Repeat steps 1 - 5 for 5 complete cycles.
- Note: A neglected barrel my require this to be repeated for many more cycles until it is smooth.
- Note: The patch will never come out clean as JB is a slightly abrasive compound and is working to polish your throat and bore
The age old question, "Breaking in the New Barrel". Opinions very a lot here, and this is a very subjective topic. For the most part, the only thing you are breaking in, is the throat area of the barrel. The nicer the finish that the Finish Reamer or Throating Reamer leaves, the faster the throat will break in.
Shoot one round and clean for the first two rounds individually. Look to see what the barrel is telling you. If I'm getting little to no copper out of it, I sit down and shoot the gun. Say 4 - 5 round groups and then clean. If the barrel cleans easily and shoots well, we consider it done.
If the barrel shows some copper or is taking a little longer to clean after the first two, shoot a group of 3 rounds and clean. Then a group of 5 and clean.
After you shoot the 3rd group and 5th group, watch how long it takes to clean. Also notice your group sizes. If the group sizes are good and the cleaning is getting easier or is staying the same, then shoot 4 - 5 round groups.
If fouling appears to be heavy and taking a while to clean, notice your group sizes. If group sizes are good and not going sour, you don't have a fouling problem. Some barrels will clean easier than others. Some barrels may take a little longer to break in. Remember the throat. Fouling can start all the way from here. We have noticed sometimes that even up to approximately 100 rounds, a barrel can show signs of a lot of copper, but it still shoots really well and then for no apparent reason, you will notice little to no copper and it will clean really easy.
This is meant as guide lines only. There is no hard and fast rule for breaking in a barrel.
Always use a good quality, 1 piece cleaning rod such as Dewey, Boretech, etc. Always use a bore guide. Whether cleaning a bolt action rifle or a semi-auto, good bore guides cleaning rods are available from a number of sources (such as Sinclair International, Champions Choice, Brownells', etc.
We prefer to use the Parker-Hale type cleaning Jags. Cut your patches to the proper size. If the patch squeaks going down the barrel, it is to tight. Roll your patches around the jag tip like a cigarette. This gives an even patch versus poking the patch in the center. When you use the latter method the patch doesn't fold evenly. Using the first method of rolling the patch, gives you more surface area and keeps the tip of the cleaning rod centered going down the barrel.
If you use a brush, we recommend one caliber smaller or an old worn out one. Roll a patch around the brush. Always push the brush, Breech to Muzzle. Remove the brush before pulling your rod back through! NEVER pull the brush back over the crown. More damage to a good barrel is done from cleaning than actual shooting. The first to suffer is the crown. The crown is the last thing the bullet touches when it leaves the gun. Any damage here affects accuracy no matter what.
Cleaning Basics:
- Good 1 piece quality cleaning rod.
- Bore guide
- Mice cotton patches
- Don't drag the brush back over the crown!
Never mix your solvents! Either in a jar or in the barrel, unless you are a chemist and know how they are going to react with one another and with the steel. Play it Safe.
Good Luck and Good Shooting!
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