The Evolution of the Ultralight Rifle PART 2: Barrels
Welcome to PART 2 of the Evolution of the Ultralight Rifle (EUR) series. If you haven't read the first article, you can find that here.
It’s not common knowledge among young American hunters and shooters, but the rifles we use today owe a lot to the final iteration of Paul Mauser’s German carbine, the K98. The same goes for our own 1903 Springfield. These two venerable weapons were the most common bolt-action infantry rifles in Germany during the WW II conflict.
Both were exceedingly accurate and reliable for their time, but what happened to the rifles after reaching the rich, freedom-fertile US soil after the war helped further shape the landscape of the US hunting and shooting scenes. Quite often, the rifles were sporterized; cut down, re-stocked, and generally lightened up. For example, simply outfitting the k98 with a sporter stock and removing the cleaning rod and bayonet lug easily shaved a 16 or 20 ounces off the nearly nine-pound gun.
If the enduring pursuit of lightweight accuracy had wheels, the bolt guns of WWII had set them in motion.
Over the years, US firearm manufacturers and custom gunsmiths perpetuated the trend in response to the growing demand from hunters and shooters for better, lighter rifles. At some point in the late 1980s, most big-name rifle companies offered synthetic stocks, thin barrels or barrel fluting in light weight models. For serious mountain hunters, skeletonizing parts also became more common, and aluminum gained popularity for components like scope rings, mags and bottom metal.
But that’s where the big wheels of progress began to slow. Over the following decade or so, aftermarket stocks got a little lighter and scopes dropped an ounce or two, but few if any major strides were made to couple significant weight reduction with long range or extended use performance. Only so much metal can be removed from an action or barrel without inverse affects to repeatable accuracy, ceteris paribus.
So there we wallowed for a decade or so, in our own wreaking pool of complacency and in desperate need of something new. To advance the cause, it needed to be something light, strong and proven. As is many times the case, the civilian world turned to a technology developed by the defense industry.
The British Ministry of Defense and Rolls Royce had been using carbon fiber in aircraft construction since the 1960s. Despite its exceptional strength/weight ratio, the stuff wasn’t really applied to the firearm industry until the 80s or 90s. In addition to adapting it to aftermarket stock construction, some manufacturers began forming rifle barrels by wrapping a steel core in woven carbon fiber “fabric.”
I’m greatly oversimplifying the process, but success was, debatably, marginal. The base material that would again propel the lightweight evolution had been identified, but the carbon formula, processes and bonding compounds used were in need of major refinement.
Because of the way the fibers were applied and more importantly the compounds used in the application process, the earliest CF-wrapped barrels to emerge insulated the steel barrel core, rather than offering better heat dispersion. As research progressed, heat-shedding bonding compounds and carbon fibers were applied to barrel construction. But while this initial application of high conductivity fiber excelled in heat reduction, it lacked in other areas. The barrels weren’t accurate, and the material shrunk as heat was applied.
It wasn’t until years later that a completely different production technique emerged, based on aerospace-grade materials, which gave carbon fiber the boost it needed to become a true, chest-pounding contender in barrel accuracy, consistency and longevity.
Starting in 1991, most of this research took place at Applied Barrel Systems (ABS), in Lincoln Nebraska. In 2001, patent and product production began. After a decade of making CF-wrapped barrels, ABS teamed with Jense Precision, a custom rifle company in Montana, to create PROOF Research.
Since that time, PROOF Research has pioneered and perfected the application of individual CF strands to a steel barrel blank. When paired with proprietary bonding epoxies and processes, this yields a barrel that’s as stiff, or stiffer, than a steel barrel of the same contour, while weighing at least 1/3 less, shedding heat 1/3 faster, and maintaining match-grade accuracy shot after shot.
For the mountain hunter, a lighter payload might mean climbing higher with more stamina and daylight left at the summit. With less weight in a barrel, deployed military troops could potentially carry more ammunition. For clandestine forces operating behind enemy lines, less weight could translate to maneuverability and lethality. And for the competitive shooter, a Proof Research barrel provides supreme accuracy.
Today, PROOF Research (PROOF) builds what many consider the Gold Standard for lightweight rifles and barrels. With production based in Montana, the company’s carbon fiber barrels and custom precision rifles are making waves in the outdoor/shooting industry.
Ask a pro
To learn more, I spent a lot of time on the phone with Cody Voermans. He’s the Hunting Pro Staff Manager at PROOF and Hunting Pro Staff for Kryptek Outdoor Group. But before we go on, let me qualify this guy for you.
A third-generation competitive shooter from Kalispell, MT, Cody was given a rifle on his first birthday, and fired it on his second. He started competitive shooting at eight years old and over a 17 year shooting career spent 10 years as a member of the United States Running Target Team. Four of those years were spent as a Resident Athlete at the United States Olympic Training Center in Colorado Springs, CO. During his tenure on the team, Voermans traveled the world competing in hundreds of national and international shooting events and sent over 1 million rounds down range. Now that’s a lot of trigger time.
After falling short at the 2000 U.S. Olympic Team Trials, he finished his civil engineering degree at Montana State University and focused the rest of his energy on long range shooting and big game hunting. His hunting career was already well underway by that time however.
Since he started hunting at age 12, Voermans has fired just about every make and model of hunting rifle available and taken well over 100 big game animals across 12 species of North American Game. Some of these have put his name in the Boone & Crockett record book.
Given his resume, I felt plenty confident asking Cody to provide some information on accurate rifles, and more specifically, those made by PROOF Research.
Accurate barrels 101
Voermans gave me a brisk refresher on what it takes to generate an exceedingly accurate barrel. And for the sake of this conversation, “accurate” is the ability to consistently shoot ½ MOA groups. PROOF apparently agrees, as that’s the performance guarantee they provide with each of their three complete rifle builds; the Summit, Terminus and Tac II.
To reach that level of performance, it can take more than just a match-grade, hand-lapped bore. Generally speaking, the heavier (thicker) a barrel, the more accurate it will be. This is because:
A) A thick barrel can absorb more heat than a thin barrel before being negatively affected by heat-induced expansion.
B) Because of its larger exterior surface area, a thick barrel can dissipate heat into the surrounding air faster than a thin barrel.
C) A thick barrel is more rigid than a thin barrel, simply because it contains more material. If you were to watch with an ultra-slow motion camera, you’d see that a barrel actually “whips” when fired. The more rigid a barrel, the less whip it experiences as the projectile travels through the bore, and the more consistently it will deliver that projectile to the point of aim.
These are the reasons that benchrest shooters generally use a very heavy barrel contour. And they can afford to, because they only have to hump said rifle as far as the shooting bench.
“So, if you want a super-accurate, steel-barreled rifle, you’d be well served to put a bull barrel on it – a really heavy contour,” explained Voermans. “Well, that doesn’t work for a deployed soldier or a mountain hunter. A 20-pound rifle simply isn’t feasible when weight is an important variable.”
It’s the weight saving concept that was the impetus for perfecting the carbon fiber wrapped barrel; drop significant weight while maintaining a level of accuracy and consistency often only achieved with a much heavier barrel. A complete PROOF Research rifle can weigh less than seven pounds, while providing the repeatable accuracy of a steel-barreled rifle twice its weight or more. It’s carbon fiber’s rigidity that minimizes the variable of barrel whip that so ruthlessly plagues a thin steel barrel, or what Voermans called a “noodle barrel”.
“Beyond that, a PROOF Research carbon fiber barrel is nearly indestructible,” said Voermans. “It’s impervious to the elements and almost impossible to scratch. I’ve paddled a boat with my Terminus on the Arctic Red River in Canada, and propped up a lean-tu in Alaska with the buttstock lodged in the muskeg. Being utterly soaked for weeks at a time or covered in salty sea spray has absolutely zero effect on my guns. They’re light, durable and accurate. To me there is no better tool for the mountain hunter.”
But, for those still skeptical, you don’t have to take Cody’s word for it. There’s a video online of two guys who shoot a three -round group out of a PROOF rifle, unscrew the barrel, use it like a hammer to demolish a cinder block, thread it back onto the rifle, and proceed to shoot another similar group. It’s likely the most heinous torture test ever perpetrated against a precision barrel, and you can watch it, here.
How can a CF barrel be used as a sledge hammer and still hold accuracy? It’s PROOF’s unique material, techniques and components that set them apart. And those developments are the result of many millions of dollars’ worth of private research and investment.
While the details of the carbon fiber barrel recipe are fiercely guarded by PROOF Research, I can tell you that construction process starts with a match-grade, 416R stainless steel PROOF Research barrel blank. And by the way, PROOF does sell stainless barrels as well.
“A PROOF barrel blank is turned down on a lathe to proprietary diameters,” explained Voermans. It’s then loaded onto another machine, and rotated slowly while strands of carbon fiber are applied. It looks similar to the winding of a baitcasting reel. Afterward, the barrels are cured. This is an irreversible process that converts the pliable carbon fiber strands to a rock hard, impregnable material. The entire exterior surface of the barrel is then honed flush with the shank and contoured. Sound cool? Here's a neat visual.
It’s PROOF’s proprietary fiber application process that produces the unique appearance that has, in effect, become their trademark. To some, it looks like a futuristic, grey-scale camo pattern. Others say it reminds them of fine Damascus steel. But there’s no denying it’s not the “woven” carbon fiber used on bicycles, racecars, and high-speed, low-drag tactical gloves.
“Not only is every component of a PROOF Research barrel made under one roof, but even the tools used in the process are made here, by PROOF,” said Voermans.
Safety concerns surrounded the use of CF-wrapped barrels early on. After all, when a rifle is fired, barrel pressures can approach 100,000 PSI, all contained within mere inches of the shooter’s face. Today, the technology has proven itself and it’s rarely a concern. Essentially, the carbon fiber is used to augment the strength, stiffness and harmonic deadness lost on a very thin barrel.
“The bottom line is that PROOF leaves enough steel in the core so that the barrel is safe to shoot even without a CF wrap to constrain a 65,000 PSI in-chamber explosion,” said Mike Degerness, at PROOF Research. “For comparison, it’s basically a No. 1 contour steel barrel under the CF. We know the problems associated with that light of a rifle barrel, so we made it stiffer with CF.”
“A good friend of mine has tested these barrels too, inadvertently,” said Voermans. “Two years ago, while shooting prairie dogs with a PROOF Summit .243 Winchester, he chambered a fresh round without realizing that a bullet was lodged in the bore, and sent the second round.”
At the shot, gas escaped the chamber, blowing the bottom metal off the rifle. The shooter, bewildered but unscathed, was no longer able to open the action, but the barrel showed little external damage. That exact scenario has been known to turn steel barrels into shrapnel, rupture actions, and seriously maim anyone nearby.
So PROOF’s rifles and barrels are light and safe, but that wouldn’t be worth a whole lot if they didn’t cut small groups in paper. Repeatable accuracy is ultimately what positions an industry leader ahead of other lightweight systems.
“I’ve fired 120 rounds in a single shooting session, and I can’t get the groups to open up,” said Voermans. “I’ve specifically been told by PROOF to beat the snot out of these guns, and no matter what I do, I can’t negatively impact their performance. I named my rifle Novocain, because it always works,” explained Voermans. “It’s a sub-half minute rifle all day, every day. It simply outshoots me.”
But praise has come from other professionals as well. A glance at the PROOF website yields names like Norm Crawford, Chris Gittings, Travis Gibson, Lena Miculek and so on, who’ve together won hundreds of 1st place competitive shooting trophies.
“For me, PROOF’s performance is half the reason I’ll always be loyal to the brand,” said Voermans. “Just as important, every component that goes into one of these rifles, aside from the recoil pad and trigger, is made here, in Montana, by the hands of folks I’m proud to know.”
Check out PART 3 of the EUR series of articles, where we cover custom, ultralight rifle stocks.
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