October 14th, 2019

Learn All About the Cut Rifling Process — Watch Krieger Video

Krieger Barrels Cut Rifling Cut-Rifled Barreling

How Krieger Builds Barrels

This video shows the process of cut-rifled barrel-making by Krieger Barrels, one of the world’s best barrel manufacturers. Krieger cut-rifled barrels have set numerous world records and are favored by many top shooters. The video show the huge, complex machines used — bore-drilling equipment and hydraulic riflers. You can also see how barrels are contoured, polished, and inspected.

For anyone interested in accurate rifles, this is absolutely a “must-watch” video. Watch blanks being cryogenically treated, then drilled and lathe-turned. Next comes the big stuff — the massive rifling machines that single-point-cut the rifling in a precise, time-consuming process. Following that you can see barrels being contoured, polished, and inspected (with air gauge and bore-scope). There is even a sequence showing chambers being cut.

Click Arrow to Watch Krieger Barrels Video:

Here is a time-line of the important barrel-making processes shown in the video. You may want to use the “Pause” button, or repeat some segments to get a better look at particular operations. The numbers on the left represent playback minutes and seconds.

Krieger Barrel-Making Processes Shown in Video:

00:24 – Cryogenic treatment of steel blanks
00:38 – Pre-contour Barrels on CNC lathe
01:14 – Drilling Barrels
01:28 – Finish Turning on CNC lathe
01:40 – Reaming
01:50 – Cut Rifling
02:12 – Hand Lapping
02:25 – Cut Rifling
02:40 – Finish Lapping
02:55 – Outside Contour Inspection
03:10 – Engraving
03:22 – Polish
03:50 – Fluting
03:56 – Chambering
04:16 – Final Inspection

Krieger Barrels

Pratt & Whitney Cut rifling hydraulic machine

“At the start of World War Two, Pratt & Whitney developed a new, ‘B’ series of hydraulically-powered rifling machines, which were in fact two machines on the same bed. They weighed in at three tons and required the concrete floors now generally seen in workshops by this time. Very few of these hydraulic machines subsequently became available on the surplus market and now it is these machines which are sought after and used by barrel makers like John Krieger and ‘Boots’ Obermeyer. In fact, there are probably less of the ‘B’ series hydraulic riflers around today than of the older ‘Sine Bar’ universal riflers.” — Geoffrey Kolbe, Border Barrels.

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December 26th, 2018

The Cut-Rifling Process — A Short History and Demonstration

Pratt & Whitney Cut rifling hydraulic machine

You’ve probably heard of cut-rifling, but did you know this process was invented in Germany nearly 500 years ago? Read on to learn more about how a cut-rifled barrel is made…

The cut-rifling process, used by leading barrel-makers such as Bartlein, Border, Brux, Krieger, and Obermeyer, can yield a very high-quality barrel with a long useful life. Cut-rifled barrels have been at the top in short- and long-range benchrest competition in recent years, and cut-rifled barrels have long been popular with F-Class and High Power shooters.

You may be surprised to learn that cut-rifling is probably the oldest method of rifling a barrel. Invented in Nuremberg around 1520, the cut-rifling technique creates spiral grooves in the barrel by removing steel using some form of cutter. In its traditional form, cut rifling may be described as a single-point cutting system using a “hook” cutter. The cutter rests in the cutter box, a hardened steel cylinder made so it will just fit the reamed barrel blank and which also contains the cutter raising mechanism.

Above is a computer animation of an older style, sine-bar cut-rifling machine. Some machine features have been simplified for the purposes of illustration, but the basic operation is correctly shown. No, the cut-rifling machines at Krieger don’t use a hand-crank, but the mechanical process shown in this video is very similar to the way cut-rifling is done with more modern machines.

Kolbe Border Barrels Firearms ID

Read About Cut-Rifling Process at Border-Barrels.com
To learn more about the barrel-making process, and cut-rifling in particular, visit FirearmsID.com. There you’ll find a “must-read” article by Dr. Geoffrey Kolbe: The Making of a Rifled Barrel. This article describes in detail how barrels are crafted, using both cut-rifling and button-rifling methods. Kolbe (past owner of Border Barrels) covers all the important processes: steel selection, hole drilling, hole reaming, and rifling (by various means). You’ll find a very extensive discussion of how rifling machines work. Here’s a short sample:

“At the start of World War Two, Pratt & Whitney developed a new, ‘B’ series of hydraulically-powered rifling machines, which were in fact two machines on the same bed. They weighed in at three tons and required the concrete floors now generally seen in workshops by this time. About two thousand were built to satisfy the new demand for rifle barrels, but many were broken up after the war or sold to emerging third world countries building up their own arms industry.

Pratt & Whitney Cut rifling hydraulic machine

Very few of these hydraulic machines subsequently became available on the surplus market and now it is these machines which are sought after and used by barrel makers like John Krieger and ‘Boots’ Obermeyer. In fact, there are probably less of the ‘B’ series hydraulic riflers around today than of the older ‘Sine Bar’ universal riflers.

The techniques of cut rifling have not stood still since the end of the war though. Largely due to the efforts of Boots Obermeyer the design, manufacture and maintenance of the hook cutter and the cutter box have been refined and developed so that barrels of superb accuracy have come from his shop. Cut rifled barrel makers like John Krieger (Krieger Barrels), Mark Chanlyn (Rocky Mountain Rifle Works) and Cliff Labounty (Labounty Precision Reboring)… learned much of their art from Boots Obermeyer, as did I.” — Geoffrey Kolbe

Video find by Boyd Allen. Archive photos from Border-Barrels.com. In June 2013, Birmingham Gunmakers Ltd. acquired Border Barrels. Dr. Geoffrey Kolbe has set up a new company called BBT Ltd. which produces chamber reamers and other gunsmithing tools and gauges. (Thanks to L. Holland for the Kolbe update).
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August 21st, 2018

Barrel Break-In — Essential Procedure or Total Waste of Time?

Barrel Breakin Break-in conditioning cleaning Wade Hull Shilen Walther Varminter.com Eric Mayer Video interview barrels
Photo courtesy Sierra Bullets.

The question of barrel break-in is controversial. Some folks advocate an elaborate, lengthy cycle of shooting and brushing, repeated many times — one shot and clean, two shots and clean and so on. This, it is argued, helps barrels foul less and shoot more accurately. Others say minimal break-in, with patching and brushing after 10-15 rounds, is all you need. Still others contend that break-in procedures are a total waste of time and ammo — you should just load and shoot, and clean as you would normally.

We doubt if there will ever be real agreement among shooters concerning barrel break-in procedures. And one must remember that the appropriate break-in procedure might be quite different for a factory barrel vs. a custom hand-lapped barrel. This Editor has found that his very best custom barrels shot great right from the start, with no special break-in, other than wet patches at 5, 10, and 15 rounds. That said, I’ve seen some factory barrels that seemed to benefit from more elaborate break-in rituals.

What’s the best barrel break-in procedure? Well our friend Eric Mayer of Varminter.com decided to ask the experts. A while back Eric interviewed representatives of three leading barrel manufacturers: Krieger, Lothar-Walther, and Shilen. He recorded their responses on video. In order of appearance in the video, the three experts are:

Wade Hull, Shilen Barrels | Mike Hinrichs, Krieger Barrels | Woody Woodall, Lothar Walther

Barrel Breakin Break-in conditioning cleaning Wade Hull Shilen Walther Varminter.com Eric Mayer Video interview barrelsDo I Need to Break-In a New Rifle Barrel?
Eric Mayer of Varminter.com says: “That is a simple question, [but it] does not necessarily have a simple answer. Instead of me repeating my own beliefs, and practices, on breaking-in a new rifle barrel, I decided to answer this one a bit differently. While we were at the 2016 SHOT Show, we tracked down three of the biggest, and most popular, custom barrel makers in the world, and asked them what they recommend to anyone buying their barrels, and why they recommend those procedures. We asked the question, and let the camera run!” Launch the video above to hear the answers — some of which may surprise you.

Long-Term Barrel Care — More Experts Offer Opinions
Apart from the debate about barrel break-in, there is the bigger question of how should you clean and maintain a barrel during its useful life. Some folks like aggressive brushing, other shooters have had success with less invasive methods, using bore foam and wet patches for the most part. Different strokes for different folks, as they say. In reality, there may not be one solution for every barrel. Different fouling problems demand different solutions. For example, solvents that work well for copper may not be the best for hard carbon (and vice-versa).

CLICK HERE for Long Term Barrel Care Article »

Shooting Sports Lohman Barrel

Chip Lohman, former Editor of Shooting Sports USA Magazine, has authored an excellent article on barrel maintenance and cleaning: Let the BARREL Tell You — Match Barrel Care. In this article, Chip shares the knowledge of a dozen experts including respected barrel-makers Frank Green (Bartlein Barrels), John Krieger (Krieger Barrels), Dan Lilja (Lilja Barrels), and Tim North (Broughton Barrels).

“Why worry about a little barrel fouling when the throat is subjected to a brutal 5,600° F volcano at 55,000 PSI? To investigate these and other questions about taking care of a match barrel, we spoke with a dozen experts and share their knowledge in this first of a series of articles.

After listening to folks who shoot, build barrels or manufacture cleaning solvents for a living, we concluded that even the experts each have their own unique recommendations on how to care for a match barrel. But they all agree on one thing — the gun will tell you what it likes best. Because the life expectancy of a match barrel is about 1,500 to 2,500 rounds, the objectives of cleaning one should include: preserve accuracy, slow the erosion, and remove fouling — all without damaging the gun. This article doesn’t claim that one cleaning method is better than the next. Rather, we set out to interject a little science into the discussion and to share some lessons learned from experts in the field.” — Chip Lohman

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May 9th, 2017

High-Tech Honing — Major Advance in Barrel Making

Sunnen honing barrel hone CNC computer honer machine Pac-nor

Some custom barrel makers are now honing barrels (after drilling) to improve bore diameter uniformity, smooth the interior finish, and reduce barrel lapping times. For years, large-scale manufacturers of hammer-forged barrels have employed honing. Now the process is being used by smaller, “boutique” barrel-makers. This article explains how and why barrel honing is done. Take the time to watch the video. For anyone with an interest in barrel-making, this video is an eye-opener…

Barrel Honing Process Demonstrated (Worth Watching!):

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

For custom barrel makers, honing is a time-saver and cost cutter. A few minutes on a honing machine can cut lapping times in half, leaving a cross-hatched surface finish in single or low double-digit Ra. Honing is the same process used to make diesel fuel injectors with bore roundness and straightness controlled to fractions of a micron (<0.000040″), with surface finish Ra ≤0.15 µm (6 µin).

A key manufacturing process used for hammer-forged barrels is now getting attention from the makers of custom button-rifled barrels. This process is precision bore-honing. Honing produces a high-quality bore surface fast, which is critical to hammer forging. (Why is honing so important with hammer forging? Surface finish is the one feature of the barrel that cannot be controlled in hammer forging. Surface imperfections in a barrel blank tend to be amplified as the blank is formed on the rifling mandrel. And if the bore is chromed afterwards, imperfections in the surface finish become even more obvious.)

Honing dramatically improves bore diameter size uniformity and accuracy, surface finish and roundness throughout the length of the barrel. It can certainly be used in place of a pre-rifling lap. The chief difference between a lapped and honed bore is the direction of the finish lines in the bore. Honing leaves fine spiraling crosshatch lines, while a lap leaves lines going longitudinally in the bore. After rifling the manufacturer can remove the crosshatch finish with a quick lap if desired. Honing is fast, accurate, and can be automated. Its surface quality and geometry can duplicate lapping, except for the longitudinal lines of the lapped finish.

Frank Green of Bartlein Barrels told us: “We worked with Sunnen and we did all the initial testing on the prototype machine for them. The machine works great! We ordered and received last year a new manufactured machine with the changes we wanted on it and we just ordered a second one a month or so ago. Should be here next month.”

(more…)

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April 1st, 2015

Gun Tech: Top Barrel-Makers Adopt Degaussing Technology

Advancements in barrel technology in recent decades have been impressive. Today’s premium barrels deliver accuracy that could only have been dreamed-of decades ago. And now a new development promises to help barrel-makers craft the most uniform, consistent, and stable barrels ever.

What’s the new technology? You may be surprised. It’s not a surface treatment, or a cryogenic bath. The latest development in barrel manufacturing is Degaussing — the process of de-magnetizing metal objects. Degaussing is now used in many industries to uniform metallic products and to prevent unwanted interactions with magnetic fields. LEARN MORE.

Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss.

At the recent IWA show in Germany, Vallon GmbH, a German manufacturer of degaussing machines, told us that two major Wisconsin barrel-makers have purchased Vallon industrial degaussing units. The units sold to the American barrel-makers are similar to Vallon’s EMS unit show below. This can degauss (i.e. de-magnetize) 50 barrel blanks in one pass.

Barrel degaussing Vallon Kreiger Bartline Wisconsin IWA Show Navy James Crofts

The Vallon degausser works by passing the barrel steel through a coil. Vallon explains: “The density of magnetic field lines is at its maximum in the coil centre, and is strongly decreasing towards the outside. If a ferromagnetic work piece (steel) is introduced into the coil, the field lines are concentrating and flooding the work piece. The conductivity of steel is up to 800 times higher than that of air. Degaussing is done during a continuous movement of the work piece, leading out of the coil. Decreasing field strength is achieved by a slow extraction from the coil.”

Barrel degaussing Vallon Kreiger Bartline Wisconsin IWA Show Navy James Crofts

How Degaussing Improves Barrel Steel and Rifle Performance
So what does magnetism have to do with barrel performance? How can degaussing help make a barrel better? Vallon’s scientists tell us that degaussing has three major benefits. First, it aligns ferrous elements within the barrels, strengthening the steel at the molecular level from the inside out. Second, by reducing static surface charges, degaussing reduces chatter during drilling, which creates a straighter bore with a better surface finish. Lastly, there is evidence that degaussed barrels produce slightly more velocity. When a copper-clad bullet spins through a non-degaussed (magnetically-charged) barrel, this creates waste electrical energy. The energy expended reduces velocity very slightly. You can see this effect yourself if you spin a copper rod in the middle of a donut-shaped magnet. This creates an electrical charge.

Here a barrel is checked after degaussing with a Vallon EMS. The meter records a zero magnetic value, showing complete degaussing success.
Barrel degaussing Vallon Kreiger Bartline Wisconsin IWA Show Navy James Crofts

Degaussing Will Add $50.00 to Barrel Cost
We know what you’re thinking: “All right, degaussing seems beneficial, but how much will this add to the cost of my new barrel?” Based on off-the-record conversations with two barrel-makers, we estimate that degaussing will add less than $50.00 to the cost of a new barrel blank. That’s a small price to pay for greater accuracy and barrel life.

Barrel degaussing Vallon Kreiger Bartline Wisconsin IWA Show Navy James CroftsAsk a Sailor — F-Class Champion and
U.S. Navy Veteran Explains Degaussing

We asked reigning F-TR Champion James Crofts about barrel degaussing. A U.S. Navy veteran, he immediately understood the potential benefits of this process. “I served in nuclear submarines. Since before World War II, the U.S. Navy degaussed its subs and smaller warships. This had many benefits. Principally, it helped reduce the risk of triggering magnetic mines. But that wasn’t the only benefit — the degaussing process gave the steel greater resilience and longevity. And that’s why the Navy degaussed non-combat vessels as well. Will a degaussed barrel shoot better? Honestly I can’t say. But based on my Navy experience, I bet degaussed steel will be more uniform and will last longer. I’m glad somebody is trying this out on rifle barrels. Put me on the waiting list!”

Barrel degaussing Vallon Kreiger Bartline Wisconsin IWA Show Navy James Crofts

The above photo show a U.S. nuclear submarine during a degaussing (also called “deperming”) session. This reduces the vessel’s electromagnetic signature, making it more stealthy. Deperming also adds to the vessel’s longevity. With steel-hulled ships, static electricity builds up as the hull slices through the water. A powerful, constant static charge will cause the steel to deteriorate. Degaussing (deperming) helps prevent this, extending the life of the hull.

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March 3rd, 2014

Krieger Barrels — Like Father, Like Sons

Krieger Barrels John KriegerKrieger Barrels Inc. is a family-run business. Founder John Krieger now works with two of his sons in the business, Andrew (“Andy”) and Mark. At SHOT Show 2014 we had a chance to chat with John and Andy. John told us that he is very proud to work with his two sons. He said that Andy, who has a degree in engineering, brings an important skill set and a new level of scientific expertise to the business. On his part, Andy says that his father is a “great boss… and the best teacher you could have”. Meet this father and son barrel-making team in this short video.

John Krieger and Andrew Krieger

How does Krieger Barrels produce such a great product year in and year out? It takes a lot of highly-skilled labor and some serious machinery to produce outstanding cut-rifled barrels. To illustrate the barrel-making process, Krieger has produced a fascinating video, filmed at Krieger’s production facility in Richfield, Wisconsin. This video shows the process of single-point, cut-rifled barrel-making start to finish. If you love big, powerful machines, you’ll enjoy this video. Its really quite amazing to see all that’s involved in the production of cut-rifled barrels.

How Krieger Barrels Are Made (MUST-WATCH video — one of the best we’ve ever featured).

For anyone interested in accurate rifles, this is absolutely a “must-watch” video. Watch blanks being cryogenically treated, then drilled and lathe-turned. Next comes the big stuff — the massive rifling machines that single-point-cut the rifling in a precise, time-consuming process. Following that you can see barrels being contoured, polished, and inspected (with air gauge and bore-scope). There is even a sequence showing chambers being cut.

Here is a time-line of the important barrel-making processes shown in the video. You may want to use the “Pause” button, or repeat some segments to get a better look at particular operations. The numbers on the left represent playback minutes and seconds.

Krieger Barrel-Making Processes Shown in Video
00:24 – Cryogenic treatment of steel blanks
00:38 – Pre-contour Barrels on CNC lathe
01:14 – Drilling Barrels
01:28 – Finish Turning on CNC lathe
01:40 – Reaming
01:50 – Cut Rifling
02:12 – Hand Lapping
02:25 – Cut Rifling
02:40 – Finish Lapping
02:55 – Outside Contour Inspection
03:10 – Engraving
03:22 – Polish
03:50 – Fluting
03:56 – Chambering
04:16 – Final Inspection

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September 14th, 2013

Criterion Barrels Opens New Facility in Germantown, Wisconsin

Criterion barrelsCriterion Barrels, producer of high-quality, button-rifled barrels (with a heritage of barrel-making from Krieger barrels) has opened a large new production facility in Germantown, Wisconsin. Over the past year, Criterion has hired many new skilled technicians to work in the new 72,000 square-foot facility, and new high-tech machinery is on its way.

Criterion reports: “To successfully meet with the recent industry-wide surge in demand, we have increased our production levels with the intent of fulfilling orders in the timeliest possible manner. To meet these manufacturing goals while simultaneously fulfilling our commitment to produce of some of the finest quality rifle barrels available, Criterion has successfully relocated its operations to a new 72,000 square-foot production facility. The phased transition from our Richfield workspace to the now fully-operational Germantown building was completed in November of last year.

Criterion has increased the number of its production personnel by more than 75% over the course of the last year… The purchase of new machinery will also serve to complete orders in a more efficient manner, allowing for improved material handling and reduced turnaround times[.] [R]est assured that Criterion Barrels, Inc. will continue to make all possible efforts toward streamlining and expanding our production potential while retaining the level of quality and precision that our customers have come to expect from our barrels.”

Criterion barrels

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