running in barrels.

[bruce moulds]

over the years I have come to this conclusion, which was finalized when running in a barrel using a bore scope.
there are 2 areas of interest to run in.
first area is tha actual barrel itself i.e. bore and grooves surfaces.
these surfaces are usually lapped in the types of barrel used in fclass.
we are told that the lay of imperfections is from chamber to muzzle, giving little opportunity for these surfaces to cause fouling.
we are trying to let the bullets burnish this area to a finer finish for bullet travel, and this is not a big deal to achieve.
the other area, as described on the Krieger website is the throat, which is cross hashed by reamer marks and is in effect an abrasive area to bullets.
this abrading of the bullets, in an environment of super heated flame, causes jacket material to atomize, and settle on the barrel further down as it cools.
it seems to me that no ammount of burnishing by a soft bullet can burnish this area clean and smooth.
I do not recall seeing this area come smooth until single shots have long been dispensed with. I used to clean singles until copper went away, before going to doubles, and so on, and this sometimes took all day or longer.
the scope showed that only 3 shot strings or longer started to smooth the angled throat.
I now do 3 singles, a double, a triple, and then do 5s until it smooths up, which happens much more rapidly the new wayonly when the throat is smooth will jacket fouling go away.
but you do not want to burnish the bore irregularly due to fouling, so some cleaning is necessary along the way.
there seems to be some benefit in cleaning every 10 to 12 for the last 40 to 48 shots.
keep safe,
bruce.

[jasmay]

Bruce, this may seem like a naïve question, but, what is the point of running in a barrel in this method? How much barrel life/accuracy difference are you really noticing?

My last 2 barrels I ran in by manufactures advice, which was ten shots, they then seemed to perform excellent.

I did my first barrel in the manner you speak I I was unable to notice any difference.

I know run in is a contentious issue, but I have yet to see any conclusive evidence.

Would be interested to hear your views on the subject.

[Norm]

Just about every barrel I have run in was different.

I've had Pac-Nor barrels that were like glass they were that smooth and easy to clean from shot one. They have all been very accurate too.

Had a another brand that was a dog and took 300 rounds to come good even with very careful cleaning from shot one.
Every Lilja barrel has come good very quickly.

The Archer barrel that I run in on Saturday felt quite rough but cleaned up ok. Started with ones and two's. Went to three shot groups. Then did a 13 a and a 15 shot string, cleaning between each string.
There was quite an improvement between the first and second string in both how the barrel felt on the patch and how easy it cleaned up.

Have a read on how Border barrels recommend their barrels to be run in. That would have to be the slowest method I know.

I think the steel that the barrel is made from has a lot to do with how they run in. Also piloted reamers and how the chamber is cut also plays a part.

[bruce moulds]

jasmay,
you nailed it when you say it is contentious.
I suppose what iam doing here is trying to clear my own thoughts which are changing, in an environment where others with experience in this matter think about the same subject.
whatever, barrels seem to clean up better, and copper foul less after a number of shots.
norm,
your comment re cleaning up better after that 13 shot string ties in with my thinking.
I have often wondered if edm chambering would leave a nice smooth throat.
keep safe,
bruce.

[AlanF]

Bruce,

You and I have both had 6.5-284s, so have bought barrels at a higher rate then most, although in total I'm sure you're well ahead.

I now think similarly to you about it. Get a recipe that works (I use 1-1-1-2-4-7 shots followed by a 2+10 etc.), and stick to it without paying too much attention to the rate of coppering. As the number of shots increases, I find that the total coppering stays about the same. But between every stage I keep cleaning until every last hint of copper is gone - that is a key requirement.

Alan

[BATattack]

i recently ran in 2 identical barrels at the same time while examining everything with a borescope.

I did 1-1-1-2-2-3-3 shoot it!

the carbon came out of both barrels exactly the same.

I thought I would see a lot of copper at the throat where the projie came in contact with the freshly cut lands. that wasn't the case.

one barrel coppered worst at the muzzle and reduced back toward the chamber and had virtually disappeared by half way down the barrel. ie no copper from the middle of the barrel to the chamber.

the other barrel had the worst copper in the MIDDLE of the barrel and progressively got better toward the muzzle.

what I found after doing the above listed run in process was that I was still getting a fair amount of copper and was bored of cleaning! haha so I just shot them . . . . . . . . after that I got less copper after 24 rounds than I was getting after 3. logic would tell you that copper would continue to build up the more rounds fired but it seems that consecutive rounds can actually remove copper from a good barrel.

sounds stupid but that's exactly what I saw.

I have two more identical barrels (with consecutive manufacturing numbers) and im going to run one in as per standard practice . . . . . and the other im just going to shoot without any run in and see what happens

[bruce moulds]

adam & alan,
what you say supports my growing theory, that it is the longer strings that smooth up the rough throats caused by reamers, and the singles burnish the bore.
keep safe,
bruce.

[fclass556]

Attached is an interesting article from 6mmbr and must admit one I subscribe to. A well known gunsmith here in Victoria who has done all my rifles the past decade once said "Just put a couple of rounds through it, then shoot it. All you need to do is knock the burrs and sharp ends off and DONT CLEAN THE LIFE OUT OF IT !! All those barrels had more than 3500 to 4000 rounds through and shot like stink to the end. The only reason for re barrelling was the throats getting too long and barrel too short. Maddco stainless No7 heavy profile barrels in 224 and 6mm.

Just another perspective that works for me anyway. Cheers. Andy D

QUOTE FROM 6mmBBR

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.

[jasmay]

Great post Fclass....

I remember reading that ages and ages ago, forgot where it was...

This reminds me of why I stopped using abrasives, now only giving it a touch if i notice pressure increasing, usualy as a result of copper in the throat. Rod Davies helped sort that issue for me earlier this year and put me onto iosso.

Its interesting all the different views on run in, personally I have to agree with the experts, after the first 5-10 shots, shoot like normal, any gains or benefits from that point are going to be that minimal I think you will fail to notice.

[AlanF]

Andy,

I think the best thing you said in that post was "works for me". Rifle cleaning methods would rank up there with fixes for bad backs in terms of the number of "best" methods. .

I think the best opinions about it will generally come from experienced successful shooters. Barrel makers are experts at making barrels, metallurgists know a lot about metals, and gun smiths about fitting barrels, but it is the shooter who has tried many concoctions and methods in many barrels and whose gear is consistently accurate throughout Queens shoots whose opinion I respect most on things like this. The trouble is most of them keep it to themselves .

Alan

[bartman007]

FWIW: I have been using Krieger barrels for many years, and have followed the following round count, which is very close to Bruce's:

1,1,1,2,2,3,3,5,5 = 23 shots

So basically, if there is no real copper fouling after the 5 shot strings, then I know I've got it sorted.

It doesn't seem to show much difference between 1:12 twist or 1:8 twist barrels.

After 50 rounds, I start load development. Once up to 150 -> 250 rounds I hope to get a load working.

[Norm]

Bartman,
Interesting comments on round count to load development.
I think you are right on the money. Trying for a good load is a waste of time until the barrel has had a period to "settle in".

I don't bother even thinking about load development until my barrels have had about 70 rounds down the tube. I think the smaller the calibre the less rounds are needed to "setting in".

[bartman007]

Norm,

I usually work on speed first to find a consistent patch that is in the zone that I'm after.

That gets the count up to around 150, so by then I believe the barrel has settled in, and is ready to show good groups if the load is tuned appropriately.

Of course with any new chambering, you have new brass that needs fire forming case trimming and turning etc, all of which ups the count quite quickly.

I got over 300 rounds down the tube before I had loads developed for the 6.5x47L just recently. Part of that was due to having to get the neck clearance correct by turning the cases. That was by design, as the reamer had a tighter neck.

Cheers.

[Norm]

I got over 300 rounds down the tube before I had loads developed for the 6.5x47L just recently. Part of that was due to having to get the neck clearance correct by turning the cases. That was by design, as the reamer had a tighter neck.

Cheers.

That sounds familiar. I had the same issue with my .284.
Its a bugger when the neck diameter stamped onto the barrel does not match up with what the neck diameter actually is.