Home Forums Hunting & Shooting BPCR Article on barrel break-in process posted

Guys,

I just posted a new article titled: Barrel Break-In Process. It details Badger Barrels’ process and Lee Shaver abbreviated technique. If you’re interested, click on the following link.
http://www.texas-mac.com/Barrel_Break_in_Process.html

Wayne

Smart men!

I quit formally breaking in hand lapped barrels several years ago. It is a waste of barrel life. Get a bronze bore brush and put a little 0000 steel wool and put it in your electric drill and clean the fluff left from chambering. Clean your barrel with JB or Iosso and it is broken in. I do have a borescope to verify this.
Tell me how shooting and cleaning will do a better job than the MFG. when he laps them.

OK Butch, I'll tell ya',.....no that's not quite right, I'll tell ya' what Ernie told me, and I BUY it.

This article is now OLD, and was in SSE at the very least 10 years ago. I'd pay PARTICULAR attention to the fascinating tidbit about WRINGING the barrel on it's longitudinal axis, and
actually, alla' the rest of it.

FWIW, I'm told that Kreiger pretty much feels the same way.

Always amusing whatching a peanut gallery of "Gunsmiths who have to earn a living" challenge the fellow who DEVELOPED the damned steel, and MADE the barrel.

.....after all, ....wtf would THEY know about any of this?

Building and successfully running low pressure BPCR AIN'T about smokeless BR guns, Mr Lambert.
........in some regards not even in the same universe.

GTC


Educating a "Dumb" Piece off Steel

“4140 chrome – moly steel” does have a nice ring to it, and fits quite nicely into a promotional spiel.

On the other end of this equation we find the quality obsessed R and D type who will fine tune and continually “tweak” his metallurgical formulation on a batch to batch basis. Based on his lab testing and “in the field” performance Ernie Stallman, up at his barrel works in Bristol, Wisconsin is a classic example of this breed. Deletion of those alloying elements contributory to “burnout” has been a key factor in the renowned longevity and performance of his superior barrels. His unique specification alloy steel, hot rolled, quenched and tempered, machine straightened double stress relieved is, from the mill, anything but a line item. Double de-gassing, in the crucible, deals with austenite in vapor form. (*Note: … in simple terms, an austenitic structure would be a desirable characteristic in a casing for an artillery shell or grenade casing … this is the last thing one would wish to see in a rifle barrel). The double de-gassing eliminates 92% of this phase, as performed at the mill. We can note, at this point, that Badger Barrels specifically requests that no cryogenic treatment be performed on their product. Your new Badger Barrel has already received an in-house cryo-treatment. (at ? º below 0º F) the 8% austenitic structure is fractured and a subsequent “heat soak”, at 760º F. ensures refinement of a tough, ductile martensite grain structure. (*Note: in simple terms, a martensitic structure would be a desirable characteristic for a truck axle, or a fine wrench). Volumes of material are available on this subject, for those interested. This is but a “thumbnail sketch”, in the broadest of terms, and should be regarded as such. To put this in a nutshell: stress relief, taken to a very advanced level, is a vital pre-cursor to deep hole drilling and rifling. This superior raw material, and superb precision machining practice implemented in a “for shooters, by shooters” company mindset combine to give us barrels that, in this scribes humble opinion, are far superior to that produced hitherto … anywhere, anywhen. As far as fine, accurate rifle barrels go, these are the good old days.

Jacketed Bullet Break In … Some Whys and Wherefores

In predictably infrequent discussions with Mr. Stallman, I’ve developed a healthy respect for his application of metaphor in discussing metallurgy, machining, and rifle barrels. I’ve also come to realize that he’s developed his unique and amusing syntax by way of illuminating dark and mysterious areas for his customers. Here are a few particularly interesting examples:

A New Unfired Badger Barrel …”Dumb Piece of Steel” “needs to be given a place to go home to, and educated as to how to get there.” *Note: … in this little treatise we will, henceforth call this Home Registry.

The freshly lapped interior surfaces of a barrel …“soft and fluffy”.

Choices of steel alloying characteristics and resultant machinability and “workability” for cut rifled vs. button rifled:
Cut rifled … “Marble” … since the grooves are generated by a chip forming process, a very tough, tenacious and durable material can be used. With proper stress relief practice, little or no stress is induced during the rifling process.
Button rifled … “Clay” or “Bread Dough” the chosen raw material must have a certain amount of malleability, with work hardenability occurring as the button “irons” in the grooves. An unavoidable by-product of this process is a certain amount of included “hoop stress”. When excessive levels of this sort of stress is present we encounter a barrel that “won’t settle down”.

On the highly visible (though in practical terms so minute as to be impossible to measure) features that can be induced in the “soft and fluffy” surface of a fresh lapped bore …. “contradictory marks”. “These can be induced by nothing more invasive than a bit of debris on a cleaning patch.”

Well, this brings me to a point from which I can, safely and in sincerity, make a declarative statement … having a bore scope in one’s hand does not necessarily empower one with the ability to interpret, or understand, what one is seeing (or thinks he is seeing). Quite a few hours should be invested in the inspection of as many barrels as one can get his hands on before making any claims whatsoever … and one should be shooting, cleaning, and inspecting these barrels as the curriculum evolves.

For an investment no larger than that involved in a scoped factory sporting rifle, one can procure a fine quality bore scope. This is great, a fantastic asset for any dedicated rifle nut. Sadly, there are those who, shiny new toy in hand and with no study or practice, don the mantle of expert (self appointed, what?). Beware their dissertations and extrapolations, unfounded in good technical knowledge. This is not to say that the application of these now readily available bore scopes hasn’t generated some really fine text … it has. (Read Brian Pearce’s excellent work “Barrel Break In … Pros and Cons” Rifle magazine, Wolfe Publishing, July 2004).

In brief, Mr. Pearce based his article on his jacketed bullet break in procedure (and research) with a new badger barrel C. Sharps ’74 Sharps as his test bed. He wrapped black and white pieces of tape around the bore scope recorded the radial orientation of “flaws” or perceived asperities and periodically examined them as the break in went forward. Through the progression he watched the referenced “flaws” disappear (Were they “flaws” or simply “contradictory marks” in the fresh lapped “soft and fluffy” surface?) His thought provoking and well written article is worth reading.

In counterpoint we should all simply remain aware that some bogus data has circulated as well, be it in text, chat room or rumor mill venue, that was generated by unqualified evaluation of visual imagery. Let’s let it go at that.

I’m going to pick up the shoot one round clean and cool between shots practice pre-assuming that the reader has the basic nuts and bolts of this procedure already under his belt. Let’s bat some of it’s finer, and perhaps not readily obvious, points around.

Jacketed bullets … can you “lap” a bore with ‘em? Well, not really. Some surface enhancement will take place with successive shots as the “fluff” is longitudinally burnished forward and any contradictory marks will disappear. In terms of machining process vocabulary this is not a lapping process. In point of fact, I think I’m shaky at calling it a burnishing process (where one expects the burnishing tool to be harder, and smoother than the workpiece). Suffice it to say that some re-orientation of surface micro features takes place longitudinally, on a breech to muzzle axis, and this is probably best defined as burnishing, albeit subtle, and very gentle.

What about all those “scratchy” looking longitudinal marks I see in these big bore (40 cal. and larger) barrels particularly the BPCR barrels? … The “scratchy marks” are there by design, the bigger the bore, the coarser the grit designated as final lapping grade. You’ve got to have room for bullet lube. The mirror finish, glass smooth surface you see in minty originals are the result of paper patching, which will polish a bore. Experience has shown that this finish will lead foul to a higher degree than the courser finish.

How does the jacketed bullet break in relate to the throat and leade area of my new or rebarreled rifle? Is this part of the equation? Yes, emphatically so … particularly in the custom alloy formulation of a Badger barrel. As stated before (“Big Five in Cartridge Rifle Accuracy … a Quality Barrel”, July 2003). This is a work hardening material, and demands sharp tooling. One thing anyone who works regularly with this material will observe is that, when cutting in an exterior dovetail, a tendency for this tough material to roll up a burr, or wire edge at the cutter exit surface; e.g., the downside of the cut. Now, on the exterior surface, removing this little bugger is a snap, you can bust it loose with your thumbnail. Well, suppose that the reamer used to chamber your new rig was a bit tired, and not perfectly sharp, or that it was also infed too slow, at too slow an R.P.M. The downside of the lands in the leade area can also roll off into these wire edge burrs. And gettin your thumb in there to snap ‘em off don’t seem practical, does it? While this particular “flaw” in a chambering job should not be encountered regularly, that is, the use of brilliantly sharp reamers being assumed, and with correct application of cutting fluid, feeds and speeds … Mr. Stallman nonetheless advises that he sees “problem barrels” with this flaw all too often. (And I don’t blame him for getting a bit aggravated about it, I would to!) You know guys, that a barrel maker can’t be expected to take responsibility for poor machining practice performed offsite, but apparently there are those that see this differently. That little rant executed, I’ll get back to the issue at hand … minor asperities in the downside of the leade. Remember you can snap these off, cleanly, can you but reach ‘em. The bullet jacket material on your break in slugs will engage these micro burrs and clean ‘em off. I view this as probably more critical to good performance than tidying up contradictory marks. I reckon a couple of matches takes perfect care of that issue.

I hope this has gotten your attention, and that you’re really focused on this text because there’s one more really critically desirable benefit accrued by correct jacketed bullet break in. That old saw “as the twig is bent, so grows the tree” applies, in principal. The title byline “Educating a Dumb Piece of Steel” will apply. And if you care one whit about the mechanical/structural characteristics of your barrel, for its’ entire lifetime, right down at a basic metallurgical level, well, that too will apply. I do believe that this is the first time this material appears in a firearms publication, and will do my best to present it in a coherent fashion.

Home Registration … What on earth does that mean? … Your new, fresh, “soft and fluffy” “dumb” Badger barrel has been double stress relieved and, you might say, is in a very relaxed and laid back condition (my kinda metaphor). Your shoot/clean/cool break in protocol will “wring” the barrel on its’ bore axis. The drag coefficient of a jacketed slug, by its very nature, induces a more violent action. This is exactly what we’re after controlled violence, correctly applied. (A bit like our current global situation, what?) The one thing we distinctly, and emphatically do not want during this phase is heat. Keep things as cool as you can, and reap a substantial and lasting reward. Methodically wringing the new barrel, and its’ subsequent “snap” back to “home registry” on bullet exit are the basic curriculum of educating your dumb barrel … it will only have to be taught this once and, from an accuracy stand point, it is a lesson well learned. After Home Registry is established you will be able to shoot extended, rapid fire groups, with no changes in point of impact. Should you disregard the recommended protocol, and overheat the barrel during it’s initial training phase, the insulative quality of your fore end will cause localized excess heat on the lower radius. This will most certainly lead to a barrel that, ever after will unkink, and “walk” its’ groups. Remember, by keeping temperatures low, that at an almost mystical internal level (martensite crystalline structures settling comfortably into a ferrite matrix) your new barrel is settling down for a long hard career of good work. By patiently and correctly applying the break in procedure, you are taking responsibility for the final metallurgical refinement of a piece of brilliantly engineered and formulated American alloyed steel. I would ask at this point: Do you really want to second guess the fellow that engineered this material, and than created your great barrel from the raw billet? … I for one intend to meticulously and diligently follow my manufacturer’s instructions on break in, I reckon he knows what he’s talking about.

Footnote: Hoping that in some small way I’ve been able to illuminate a hitherto dim and murky area, I’ve got a little bit of additional cautionary advice. There are a couple of other ways that one might involuntarily induce unwanted stress in a fresh, new barrel. Actions like the ’74 Sharps and flat spring high wall require substantial dovetails on their lower barrel flat or radius, for lever and action spring and fore end blocks. A good, very snug fit is the ticket here. Overtight fit-up, requiring lots of force to drift blocks into place is just asking for trouble. A “stress raiser” in this zone could very well see a flawless chamber neck pulling out of round upon heating. Likewise, interference fit in front sight dovetails should be precise, not overtight. Obviously, any drilling and tapping operations (for fore ends or scope blocks) should be well tooled and characterized by precise depth control leaving adequate barrel wall on completion. “Involuntary gas ports” can be a source of some embarrassment.

Remember, any new rifle barrel will benefit from proper jacketed bullet break in.

Work Safe

GTC

Acknowledgements:

Ernie Stallman … Thanks for the hours on patiently “wringing this out” and your invaluable input in putting this together. Particular thanks for your unique metaphor.

Buffalo Arms … Dave, Skip, Thanks for your bottomless well of patient advice, freely distributed to all the great players in this great game, newcomer and old pro alike. Thanks particularly for the great brass and your sage advice “work with the chamber”.

Pacific Tool and Gage … Dave Kiff, I know we drive you nuts with all the wacky, off the wall, variegated chamber specs. Maybe someday we’ll come close to standardization (but I wouldn’t hold my breath.) For the time being, thanks for the great reamers.













 
  

Oh,.....FWIW, I borescoped Ron Calderone's beat up early model old Browning BPCR at THIRTEEN THOUSAND rounds,.....just after he shot that "Grand Slam". Used a hawkeye with a digital doubler, on a TV screen, e.g. 27 1/2 power.

.....NO circumfrential marks were visible, and the longitudinal marks were AWFUL, compared to those visible in a new Badger.
This was part of a "Tune up",....and the old gun went back to work.

With a good spotter (Dave Maurer ringing any bells ?) , Ron could hit ANYTHING he pointed that thing at.

What you see is not always what you get, and what you HEAR (or read) is not always RIGHT.

'bout all I have to say, at this point.

GTC

I respect your opinion Greg, but I reserve the right to disagree.

Could you perhaps "disagree" with this paragraph in more than one sentence,....break it down, tear it to pieces,
....crap all over it ?

Seriously, Butch,....did you even ATTEMPT to read and understand it?

GTC


Home Registration … What on earth does that mean? … Your new, fresh, “soft and fluffy” “dumb” Badger barrel has been double stress relieved and, you might say, is in a very relaxed and laid back condition (my kinda metaphor). Your shoot/clean/cool break in protocol will “wring” the barrel on its’ bore axis. The drag coefficient of a jacketed slug, by its very nature, induces a more violent action. This is exactly what we’re after controlled violence, correctly applied. (A bit like our current global situation, what?) The one thing we distinctly, and emphatically do not want during this phase is heat. Keep things as cool as you can, and reap a substantial and lasting reward. Methodically wringing the new barrel, and its’ subsequent “snap” back to “home registry” on bullet exit are the basic curriculum of educating your dumb barrel … it will only have to be taught this once and, from an accuracy stand point, it is a lesson well learned. After Home Registry is established you will be able to shoot extended, rapid fire groups, with no changes in point of impact. Should you disregard the recommended protocol, and overheat the barrel during it’s initial training phase, the insulative quality of your fore end will cause localized excess heat on the lower radius. This will most certainly lead to a barrel that, ever after will unkink, and “walk” its’ groups. Remember, by keeping temperatures low, that at an almost mystical internal level (martensite crystalline structures settling comfortably into a ferrite matrix) your new barrel is settling down for a long hard career of good work. By patiently and correctly applying the break in procedure, you are taking responsibility for the final metallurgical refinement of a piece of brilliantly engineered and formulated American alloyed steel. I would ask at this point: Do you really want to second guess the fellow that engineered this material, and than created your great barrel from the raw billet? … I for one intend to meticulously and diligently follow my manufacturer’s instructions on break in, I reckon he knows what he’s talking about.

I'm with cross...

I broke mine in by shooting the piss out of them!

Who put the piss in them.

Experience is a neat teacher. Broke the first Badger barreled gun in with all the hoopla, second one forgot about all the nonsense and just found a proper blackpowder load for it, and away we went. First gun has a new barrel on it already second gun is chugging away just fine.
If a person was really interested in doing a "break in procedure" on a bpcr barrel 4-500 paper patch rounds is likely the best route, plus it should teach you a little bit about proper loading and shooting of a blackpowder cartridge rifle along the way.

Greg,
I'll be honest with you. I don't understand any of it after reading it 4 times. I gave my opinion on my method and verify it with my borescope. You can do as you choose and I respect your opinion.

Well, one thing we probably all CAN agree on is that a substantial amount of "Wringing" does take place every time we touch off one of these big brutes.

Don't think so?....put down your pistol gripped rifle, and grab a straight gripped one in the same chambering, same weight category. You can feel the snappy torque reaction. You can SEE it taking place while spotting, if your shooter doesn't have a good solid hold, just watch the muzzle.

Trusting the fellow who participated at an intense level in formulating the alloy AND developing the stress relief process best suited?

I can buy into home registry, based on that.

Your call.

It really just makes common sense to take proper care of some thing you plan on using hundreds maybe thousands of times.

I'm no metallurgist, hell I just had to look at HTH to spell it.

Old Bill Ferguson WAS. He walked me through some of the basics caveman level, ternary, and quareternary Phase equilibrium diagrams. Deep stuff, from a fellow that was part of the M.I.T. team that refined and DEVELOPED Chro-mo steel. It use to pizz Bill off, he'd be trying to wise me up on alloying lead, and I'd keep steering his focus over towards ferrous,....he was really patient with me, and I look back on those visits / discussions with great fondness.

For whatever it's worth, our Community College 2 year associate's degree in technology sees phase equilibrium diagrams as applied to Austenite and Martensite in GTC 105 and 206, and many journeyman level welding and millwriting curricula cover them in some depth as well.

All of the "hoopla" is about things going on at the ELECTRON MICROSCOPE level, and well below that at the ATOMIC level. In other words fairly sophisticated metallurgy.
....... not really about what one sees (or THINKS one sees) through a 17 power bore scope.

GTC

Not a metallurgist either, but I have been known to confuse them.

Residual stress is a funny thing with metal, and will do weird stuff. Can be good, like the beneficial residual stress left after shot peening, or it can be bad, like after insufficient stress relief after cold work, such as button rifling. The old timers in my industry showed me stuff that won't be found in any text book.

I heard for years how some folks pooh-pooh break in, but now I am leaning more toward breaking in. I've noted recently Pac-nor and Krieger are both advocating break-in, if for no other reason than to get the barrel smoothed before the fouling starts to collect unevenly. There's a couple of new barrels here that will get some extra attention.

But so far all the Shiloh's gotten has been patches soaked in cold water, dry patches, and Ballistol at the end of the day. It seems to be steadily improving.

I believe any nay says would likely change their minds if they ever tried a proper breakin on a stainless steel barrel.

The ease of which a patch is pushed through a barrel after ten shots is noticeable, after 25 it clearly shows a great difference.

The same thing happens when you clean it down to bare steel between range sessions, but you learn a lot more during the shooting.

I've talked a number of barrel makers, some of them also metallurgists who make barrels with as good a reputation as any mentioned on this thread. Some of them firmly believe in things directly the opposite of several details from the break-in article. One, for instance, believes that cleaning too much of the carbon out of the bore is bad, that SOME carbon in the surface of the bore prevents copper or lead build-up.

Some would also find the admonition to not allow the barrel to heat up to any degree during break-in strange, since they do to great lengths to stress-relieve their barrels to prevent any "walking" with a hot barrel. I have seen some of those barrels at work when brand-new, and they do NOT shift POI even when shot screaming hot. And I also know of at least one brand-new barrel that took a national benchrest championship without being broken-in at all.

I have also talked so several barrelmakers who, as the article mentions, only come up with a "break-in procedure" because so many of their customers are convinced something magic happens when a barrel is "properly" broken-in, even though nobody can agree on the proper procedure.

Interesting thread.

I recently observed, over several range sessions, a shooter "breaking" in a custom drop-in 10/22 barrel with an aggressive regimen typical for centerfire tubes. Shoot five, scrub with a brush and a solvent designed for centerfires, repeat endlessly. He did this religiously because that was how the barrel manufacturer had said to do it.

An interesting psychological phenomenon is how some shooters will latch on to a guru, and treat that person's dicta like the Sermon on the Mount. You can't budge them or even cause them to question it. Another high roller at our range has a guru back east who he pays an hourly consulting fee for his advice on accuracy.

Oh to have such credibility!

Paul

I know, I'll buy a Dodge Truck,.....but chitcan the owner's manual, and follow one I get from Ford.

......that'll work.

GTC