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So you have been bitten by the precision shooting bug and you would like to take your shooting to the next level... you would like to know the why and how of a custom barrel!
Man, I remember the beginning of my own journey down that path like it was yesterday!
The single biggest contributor to a firearm’s accuracy is its barrel, and having said that, boy, not all barrels are created equal!
By now you have probably asked a few questions, chatted on some forums and maybe talked with a few different shooters about the whole notion of getting a barrel. You are no-doubt confused as to what is the “best” barrel, and how do you go about getting one installed. I am hoping that at the end of this dissertation you will be more comfortable and better informed to make your choices.
What makes a custom barrel so much better than a factory barrel?
Well, the answer is best answered by turning the question around and asking, “Why are factory barrels so inferior to custom barrels?”
Ironically enough, some factory barrels shoot very accurately, despite their manufacturing shortcomings. This is however, far from being the rule. Most factory barrels are accurate enough to be used as a hunting rifle – be that varmint or game. They are capable of putting 5 shots within about an inch at 100 yards, or in shooter-speak, “One Minute of angle”.
In addition to their accuracy issues, the tooling left behind in most factory barrels causes most factory barrels to foul with copper and powder after relatively few shots. Sometimes this improves their accuracy, as this build-up of fouling acts like a mortar to fill in barrel imperfections.
A typical factor barrel is a mass produced piece of steel. The gun drills used to ream the barrels are capable of producing results within a tolerance that is usually not as stringent as a custom barrel maker. The “straightness” of the hole must only fall between a degree of acceptable tolerances. Bends and yaws are a fact of life.
This excellent boresope vide was produced by Lilja Custom Barrels, and is viewable on the 6mmbr.com website. This GRAPHICALLY depicts the differences between custom and factory barrels!
The rifling is produced in one of two common mass-production techniques: Button rifling is created by driving a carbide plug or button, down the bore of the barrel. Little protrusions on the button engrave the bore of the barrel and create the rifling as it is pushed or pulled under several tons of force, through the bore of the barrel.
The results can be fairly good, but two problems afflict button rifled barrels: In the first place, the barrel steel is placed under tremendous stress when it is button rifled. Those stresses are relieved somewhat, but no buttoned barrel loses all those latent stresses. When the barrel heats up or is machined, the barrel can change shape or warp. Likewise, when the button is withdrawn, some of the steel springs-back into its original position and this creates undulations and areas of uneven bore diameter. A barrel may be installed onto a factory rifle, only to have the shots “walk” across the target as heat causes these latent stresses to change the shape of the barrel, and consequently, the point of impact.
The second issue is the accuracy of the twist rates. Areas of different steel density will cause the button to “drag” through the steel. It will engrave its rifling, but the angle of the rifling – the spiral it creates down the bore- will change dimensions, resulting in a less-than-advertised rate of twist. This affects the ability of a barrel to stabilize bullets, it impacts bullet velocity and it has a detrimental effect on accuracy.
By its very nature, a significant percentage of button-rifled barrels end up being imperfect. These byproducts of the process are often sold as lesser-grades of barrel at cheaper prices. If one wants to rebarrel, why not do it properly?
The second method used to produce factory barrels is a method called “Hammer Forging”. The bore is drilled in the sdame manner as a button-rifled barrel, but the barrel is pounded about its external circumference by a series of hydraulically operated hammers. They beat the barrel over top of a mandrel that is inserted into the bore. In effect buttoning pushes from the inside out, hammer forging pushes from the outside-in.
European barrel makers such as Sako/Tikka have perfected this method and make some of the most accurate factory barrel made. Their barrels still suffer from latent stresses and from inconsistency of the steel. These barrels are also not lapped (more on that later)
Here is a link to an excellent in-depth article written by Dr. Geoffry Kolbe, of Border Barrels UK. They are a very fine European cut-rifled barrel manufacturer.
Kreiger makes their barrels using a completely different process. First of all, they are extremely particular about the smelting of their steel. They order their steel in exactly the composition they want, resulting in a very high quality, highly-machinable steel. The consistency of their steel is exceptional (I frequently hear from gun builders that rave about the quality of Krieger steel).
Krieger takes all of its bar stock (The steel pieces used to make barrels) and subjects it so a process of extreme cooling in liquid nitrogen. This process (Called Cryo-treating) results in a steel with a changed crystalline structure that adds dimensional strength, stress-relieves the steel and increases resistance to sliding wear. all of these qualities are highly desirable in barrel steel.
Krieger drills their steel bars a few thousandths of an inch smaller that the bore diameter of the barrel. When that process is compete, they ream the steel to within a few ten-thousandths of an inch of what the proper bore diameter is to be.
Any barrel that is drilled with a hole that is anything but perfect is discarded for re-smelting. Krieger only sells one grade of barrel: They sell the best.
Their reamed barrels are then rifled using a process called cut-rifling. A rigid rod with a cutter blade mounted in the tip, is help stationary, while the barrel is passed over the rod. The barrel is rotated using pre-set gears, and it is pulled at a very specific rate meaning that the cutter remains stationary,but the barrel blank moves back and forth and rotates over the carbide cutter.
The barrel makes hundreds of passes over the cutter head, and each pass is EXACTLY the same as the previous. 1/10,000”: of material is removed with each pass and this in turn creates the rifling.
This process introduces ZERO stress to the barrel, and results in rifling that is ABSOLUTELY as-advertised.
The advantages to this system are numerous. In the first place, zero latent stresses. You have a barrel that can be safely fluted, cut, turned-down, mounted and chambered without risk of ANY dimensional changes. Secondly, the accuracy of the groove, land and pore dimensions is meticulous. No error in twist, no undulations down the bore and no latent stresses.
When the barrel is finished, the bore is carefully hand-lapped. A molten lead cast is made by pouring molten lead in the end of the barrel. Lapping compound is applied to the lap and it is passed back and forth down the barrel. Tooling and cutting marks are removed while giving the barrel an optimal interior finish.
Button-rifled barrels MUST have this done to even out the undulations that are left. Cut rifled barrel makers do this more as a matter of esthetics than function.
So…
You would like a custom barrel on your gun? You will simply not find a finer barrel than a Krieger Custom barrel. In my opinion, the only barrel you will find that is as GOOD as a Krieger, is the fine craftsmanship of Canadian Barrel Maker, Mick McPhee. He is a master craftsman that only produces 30 caliber barrels and only he will only provide them for guns that be builds personally. This ensures absolute precision, accuracy and professionalism.
In case you weren’t aware, since introducing Krieger to the Western Canadian Market, they have won more Western Canadian F-Class matches than any other barrel. They have been selected as the official barrel for Team Canada to the World Long Range Championships in Brisbane, 2011.
“So, all this is very nice, but how do I get one installed on my own rilfe?”
I am not about to let anyone that invests time and money on investing in the BEST barrels that money can buy, spoil that investment on an amateur installation. While I do not do any installations myself, I have a hand-picked FEW gunsmiths that I trust to install a Krieger barrel. If you are lost, or want help in going through the process of having a custom barrel mounted on YOUR gun, I will refer you to a VERY short list of exceptional gun builders who can do your project properly, and for a reasonable price.
Contact me and I will help you with the whole process.
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