CAGE 834B9 DUNS 056429420

“Incoming fire has the right of way." - Unknown

Structured Barrels®


• Harmonically treated to achieve the most advanced, high performance barrels in the world.

• Perks
– Superior cold bore performance
– Free velocity
– BC gain
– Recoil reduction
– Flatter SD
– Reduced mirage
– Little to no load development
– Greater barrel life

• Patented barrel technology

Of the major advantages advertised shooting a Structured Barrel®, one is achieving a free velocity.

Law for the Conservation of Energy

The law for the conservation of energy states energy of an isolated system remains constant for energy is neither created nor destroyed, only converted into different forms.  This applies to the chemical energy stored in gun powder that is then released upon detonation and converted into kinetic energy as a projectile accelerates.  However, this conversion is not absolute for the work done to whip and haromincally resonate the system uses energy.

Structural Stiffness

Structured Barrels® are superiorly more rigid due to its inherit structural stiffness and resulting mass distribution achieved by AUX drilling, a deep-hole drill pattern around the bore that uniplanarizes frequencies and resists sinusoidal harmonics via axial compression.  Therefore, the energy not lost whipping and harmonically resonating a barrel is gained as kinetic energy for potentially higher muzzle velocities.


Barrel whip is energy lost accelerating a bullet.  More rigid the barrel, less energy lost.

Of the major advantages advertised shooting a Structured Barrel®, one is achieving a greater ballistic coefficient (BC).

Ballistic Coefficients

Ballistic coefficient describes external bullet performance; its ability to resist drag.  Often expressed as a three digiit value,  higher the number, greater efficiency to fly down range, retaining velocity and thus resulting in less drop and wind deflection.

Sierra Bullets Exert

“Theoretically, the BC of a bullet depends only on its weight, caliber and shape. But in a practical sense, the measured BC of a bullet also depends on many other effects.  The gun can affect the measured BC value in two important ways: spin stabilization and tipoff moments. A bullet is gyroscopically stabilized by its spin, which is imparted by the rifling in the barrel. If a bullet is perfectly stabilized by its spin, then its longitudinal axis (which is also its spin axis) is almost perfectly aligned with its velocity vector. If a bullet is not perfectly stabilized (which is usually the case), the bullet may not be tumbling, but its point undergoes a precessional rotation as it flies. In previous editions of Sierra’s Reloading Manuals we have described this precessional rotation and have called it “coning” motion to aid in mental visualization of the motion. As the bullet flies, the point rotates in a circular arc around the direction of the velocity vector. Coning motion results in increased drag on the bullet, and any firing test method then yields an effective BC value for the bullet that is lower than the theoretical value.  We have never been successful in accurately predicting BC values, or determining these values by any method other than firing tests..”  – 2.4 Lessons Learned from Ballistic Coefficient Testing 


Due to the fact barrels whip, load development standards call for bullets to pass through the muzzle at an amplitude, the maximum vibrational displacement from its equilibrium, to reduce adverse effects of barrel acceleration on external ballistic performance.  There are only two positions along its entire sinusodial whip that will experience zero acceleration, and due to the fact bullets have length and cannot be evaluated as a finite point, bullets always undergo some value of pitch.  Greater the amplitude, greater the acceleration toward equilibrium, resulting in greater pitch along a bullet’s length.

Structured Barrels® are superiorly more rigid and thus have smaller harmonic amplitudes.  This results in a less vibrational acceleration and less pitch, yielding potentially a greater ballistic coefficient.


Barrel whip induces bullet pitch.  More rigid the barrel, less pitch for a higher ballistic coefficient.

Of the major advantages advertised shooting a Structured Barrel®, one is recoil reduction.


Structured Barrels® directionalize frequencies to be uniplanar for optimum cancellation (comparable to a shotgun mic). There is no way to stop harmonic reverberation within a barrel, and to achieve absolute deadness would require an infinitely stiff object – impossible. However, we can work to directionalize waves to follow the same axis as recoil versus it emanating in a radial, sinusoidal pattern creating complex amplitudes felt by the shooter.

P and S Waves

Harmonics is similar to electricity in the fact both look for a ground, described by entropy. When a barrel whips, S and P waves are propagating through the barrel at 8,000-13,000 mph, respectively, traversing the entire barrel ~5x before the bullet even exits the muzzle. These vibrations do not stop at the barrel though. Energy is translated through the rifle and (hopefully – properly) absorbed by the shooter in those critical microseconds.

Barrel Tuners

Many may not realize, P and S waves are not the same, and while barrel tuners assist barrel whip (S waves), the sheering P wave are much more complex. This also excludes the fact harmonics rapidly change with temperature (why do we expect groups to open up on a standard barrel?) so tuning a barrel in one weather condition will optimally work at that temperature. Obviously, there is a range, but at what cost in accuracy?


Creating a series of independent, physical features assists to sectionalize the barrel to resist both S and P waves. Harmonics like everything looks to travel the path of least resistance. A standard barrel is a uniform, homogenous medium, ideal for a propagating frequencies. Compare that to a Structured Barrel®, the design inherently adopts a series of shapes and features to act as roadblocks for varying wave functions, even at the surface, so the shooter feels less recoil.  

The result is a smooth, muted recoil impulse that pushes straight back, so shooters may even be able to self-spot and watch trace.


Barrel whip affects recoil.  More rigid the barrel, greater the control.

Of the major advantages advertised shooting a Structured Barrel®, one is achieving a greater barrel life.


Objects exhibit a natural vibrational frequency described by its harmonic mode, a function of material stiffness (modules of elasticity), mass distribution, and structural stiffness.  Wave functions originating from within an object look to propagate at a matching, fundamental frequency.  Sinusoidal waves that diverge from its natural frequency generate irregularities and non-repeating wave patterns that create vibrations.  Harmonics propagate efficiently through uniform objects.  Thus changing its mass distribution and structural stiffness will affect its mode and underline frequency,  while material stiffness is affected by temperature and force.


Force is derived by multiplying mass and acceleration, the rate velocity changes in respect to time.  Increasing acceleration increases the amount of force and resulting energy that can be transferred into an object through work.  Supersonic flexion, commonly referred to as barrel whip, describes rapid harmonic acceleration, and since a barrel has mass, the work done to accelerate this mass by tensive and compressive forces generates enormous energy.

The law for the conservation of energy states energy of an isolated system remains constant for energy is neither created nor destroyed, only converted into different forms.  Therefore, work applied to a barrel to undergo flexion converts into thermal energy and this principle for work to conduct thermal energy is described by the Carnot engine and is a fundamental thermodynamic concept for entropy, a high-to-low energy state.

Thermal Embrittlement

Thermal energy alters the orbital state of electrons and thus can change a material’s atomic, mechanical, vibrational, and thermal properties (among others).  This is known as a phase shift and this is the reason material stiffness is affected by stress and subsequent temperature gains when force is applied to perform work.  Stresses that exceed an object’s state for material stiffness provided by its temperature moment will result in molecular/material failure, a phenomenon called thermal embrittlement.

Harmonic Modes

Material stiffness (modules of elasticity), mass distribution, and structural stiffness are functions that describe a barrel’s harmonic mode.  When a standard barrel undergoes whip, the system works to vibrate on a sinusoidal wave that matches its natural, fundamental frequency.  However, supersonic flexion yields diverging frequencies that make the barrel rapidly accelerate with irregular and non-repeating amplitudes.  The result stresses the barrel’s material stiffness and the work acted to whip the barrel is converted into thermal energy and is absorbed by electrons.  Heat raises orbital states, altering modules of elasticity and exasperating discrepant frequencies, and this makes the material more susceptible to thermal embrittlement.  Once the stress from supersonic flexion exceeds the material’s stiffness provided by its temperature moment, throat erosion, fire cracking, and gas jetting is caused by molecular failure.

Structured Barrels® restrict this phenomenon by increasing a barrel’s harmonic mode and purposely configured to directionalize residual harmonic frequencies for cancellation.  Enhancing its structural stiffness and mass distribution (compared to a standard barrel of the same weight) restricts supersonic flexion and thus the work and stress converted into thermal energy.  This achieves superiorly more stable modules of elasticity for prolonged material stiffness and resists thermal embrittlement.  Structured Barrels are the culmination of many physics principles (harmonics, material acceleration, energy, and thermodynamics) working in concert for a harmonically dead barrel that requires little to no load development and exhibits increased barrel life.


Structured Barrels® are configured to directionalize harmonic frequencies for cancellation, and with its enhanced structural stiffness (compared to a standard barrel of the same weight), restricts barrel whip and thus the work converted into thermal energy.  Real-world example, bending metal generates heat. Why? Why would a barrel be any different?  When a standard barrel whips, the work converted into thermal energy alters material attributes (modules of elasticity) and thus makes it more susceptible to thermal embrittlement, throat erosion, fire cracking, and gas jetting faster, decreasing barrel life.  Achieving greater stiffness results in less whip and less heat for greater temperature stability, prolonging material attributes and therefore barrel life.  Structured Barrels® utilize many physics principles (harmonics, material acceleration, energy, and thermodynamics) to achieve a harmonically dead barrel that requires little to no load development and exhibits increased barrel life.

• Review import/export code(s) and requirements here.


• Structured Barrels® are 56% stiffer than a standard barrel of the same weight; calculated using aeronautical program, CEL.

• Structured Barrels® are 21% lighter than a standard barrel of the same stiffness, calculated by aeronautical program, CEL.

• Larger the OD, greater the Structural benefits.  Smaller the OD, lighter the barrel, but at the expense of rigidity; however, this will still far exceed a standard barrel.  Weight is comparable to a standard barrel if matched.

• Structured Barrels® are 38% lighter than a standard barrel with the same frequency; calculated using aeronautical program, CEL.

• Find a load in as few as 20 rounds shooting 10-grain ladder tests in 1/2-grain increments.

• The energy not lost whipping and harmonically resonating a barrel is gained as kinetic energy for higher muzzle velocities.  See INTEL for details.

• Reduce velocity migration to single-digit deviations for extended round counts.  No vertical stringing.

• Superior structural stiffness improves stability across loads, setups, and temperatures.

• Minimal barrel drift on extended round counts yields as much as +0.5 MOA of additional precision; maintaining a higher hit-rate probability.

• Smaller vibrational amplitudes results in less bullet pitch, yielding a higher ballistic coefficient and greater bullet performance.  See INTEL for details.

• Harmonic treatments directionalize frequencies to be uniplanar for optimum cancellation.  The result is a smooth, muted recoil impulse that pushes straight, so shooters may be able to self-spot and watch traces.

• Increase barrel life.

• Thermal embrittlement is a phenomenon where materials undergo molecular failure due to stresses affected by temperature and material elasticity.  Enhancing a barrel’s structural stiffness and mass distribution (compared to a standard barrel) restricts supersonic flexion and thus the work and stress converted into thermal energy.  This prolongs its material stiffness and prevents thermal embrittlement causing throat erosion, fire cracking, and gas jetting.  See INTEL for details.

• Add +500% surface area.

• Material harmonics rapidly change with temperature.  Control temperature for longer harmonic stability.

First shots after break-in | Mark and Sam After Work
Experience and analysis | Rex Review
Structured Barrels worth it? | Chase Stround DPI Precision and Chris Schmidt
Ladder test | Coastal Precision
Throat erosion comparison | Coastal Precision
CEL aeronautic program analysis | tacomHQ
Independent user compliation | tacomHQ

Applied Ballistics

Build a Barrel

• Build your Structured Barrel® 1x or in stages:

  1. Pick a barrel blank
  2. Select harmonic finishes
  3. Chamber and thread

• Prices update automatically in real-time per selected add-ons in shop.

• Pay 1x or in monthly installments.

• If 25-50% more-barrel life is attained compared to that of a standard barrel (varies by caliber as consistent cleaning and borescope utilization recommended), ROI is achieved on top of all the performance gains uniquely exhibited by a Structured Barrel®.  Larger the caliber, faster the potential for ROI.


• A deep-hole drill pattern around the bore that uniplanarizes frequencies and resists sinusoidal harmonics via axial compression for advanced recoil mitigation.

• Axial compression describes the tensive and compressive forces exerted on an object to make it bend.  Tubes are simple structures that oppose this event due to its ideal structural stiffness.  AUX drilling creates a host of tubes that work in series to reinforce the bore.  As one hole bends, one side undergoes tension and the other compression.  This triggers the hole opposite of it in the pattern to undergo compression and tension, 180 degrees out of sync, and opposing force vectors cancel applicable x-y magnitudes.  This significantly reduces supersonic flexion and the work done to generate thermal energy. 

• AUX drilling is not a sleeve.  Thermodynamic expansion coefficient deltas from different materials induce systematic stress and changes in vibrational frequency.

• Breather holes configured in a spiral pattern near the throat induce concentrated convection cooling.

• Projectiles passing through the muzzle generate negative pressure that pull columns of high-velocity air through AUX-drill finish, cooling it from the inside.

*Suppressors alter the precise location of this low-pressure zone and will dampen this phenomenon. 

• Aligns metallurgic molecular structures to reduce material micro voids, tears, and or overlaps.  This better directionalizes harmonic frequencies for cancellation and lends greater phase shift stability.

• Offset radii cored perpendicular to AUX drilling pattern around the chamber to sectionalize harmonics and impede vibrational frequency.

• Extracts pounds while maintaining maximum rigidity.

• Multi-directional threads cut in randomized sequences of length and pitch to resist surface translated harmonics and increase heat dissipation.

• Harmonics rapidly change with temperature.  Thermal entropy, a high-to-low energy state, flows like electric entropy to tips (corners, edges, etc.), areas with a high surface-area-to-volume ratio, to release excess energy and the Fallen Angel creates hundreds of tips forward of the chamber to rapidly dissipate heat.

• Collectively, adds +500% more surface area compared to a standard barrel.

• Sandblast – Creates millions of microscopic surface depressions to increase surface area and reduce glare (ideal for snipers).

• Matte Black Cerakote – Coating with zero to negative heat transfer that blacks out barrel.


• Refer to “Build a Barrel” at Shop > Structured Barrel for requirments if not sourced through tacomHQ®.

• Click here to select a final, max barrel diameter by caliber.

*Larger the OD, greater the Structural benefits.  Smaller the OD, lighter the barrel at the expense of rigidity.  However, this still far exceeds a standard barrel. 

• Select a Structure diameter per a specific stock or chassis.

  1. Assuming a high-end lapped barrel, use Tubb’s break-in bullets from the TMS kit – caliber specific. Five sets of bullets will be provided with your kit.
  2. Load ten bullets at 75-85% of charge and lube each bullet with Imperial Sizing Wax, Hornady One Shot, or equivalent to reduce seating pressure.  Set seating depth so the bullets do not engage the rifling.
  3. Thoroughly clean the bore using a brush and patches to remove particulates; this may require significant brush-force due to adhesion forces.
  4. Shoot five rounds.
  5. Thoroughly clean the barrel using a brush, patches, solvents, and detergents for 30-60 mins until you get a clean patch.  This prevents driving unwanted material into the barrel’s porosity.
  6. Shoot remaining five rounds and repeat step 5.
  7. Shoot five Burnishing Bullets and repeat step 5.
  8. Shoot 10 rounds using your specific bullet at 85% charge (metallurgies vary between manufacturers) and repeat step 5.

Complete.  At this stage, there should be a lead into the lands and any burrs from throat operations removed.

*DISCLAIMER:  Failure to follow these steps may cause inaccuracies, and voids any guarantees associated to Structured Barrels®.

• Repeat steps 1-5 as necessary for tune intervals will vary according to caliber, pressure, and bore conditions.

• Borescopes are highly recommended to guarantee a comprehensive and conistent bore cleaning.

Applied Ballistics

Standard vs. Structure

• Click here for the complete article.

“It is very important while testing barrel or point of impact drift to make every effort to isolate the different contributing factors when possible.

With this in mind all weapons were cleaned and fouled with an equal number of fouling shots [using new brass throughout the tests], chambered to the same action via a West Texas Ordinance Switch Lug, and consisted of high quality hand-lapped barrels mated to one action, load developed (Berger OTM Hybrids 105gr & 130gr) that consistently shot <1/2 MOA and averaging single digit SDs throughout entire test with action torqued in one chassis throughout test with Schmidt and Bender PMII remained mounted throughout test, and a Jewell Trigger 14oz. During the first test the Structured Barrel (green) outperformed the RPR (blue) to such a degree that data looked a little unfair and the test was ran again to confirm the results.

For the second version of the test the structured barrel (yellow) was pitted against a Bartlein 6.5mm Creedmoor (orange). As was the case with the initial RPR v. TacomHQ test, the Structured Barrel outperformed in practically every metric: smaller variation in point of impact, lower sectional temperatures, longer heat cycle, and lower variance in velocity through out the test.

The blue and gray plots show the large drift produced by the RPR which amounted to more than an MOA of drift horizontally and more than 3/4 MOA vertically. The orange plot of the medium Palma Bartlein showed nearly 1.0 MOA of vertical drift and just under 1/2 MOA horizontally. The Structured Barrel from TacomHQ showed less than 0.4 MOA drift in all directions. These plots represent four instances of 50 round shot strings and one additional 25 round shot string!

All things, as equal as they can be, the Structured Barrel setup could see +0.5 MOA of additional accuracy. During a long string of fire or long engagement, this system would maintain a higher hit probability than a conventional barrel.
The conventional barrel reached temperatures of 180°F while the Structured Barrel remained 17°F cooler.”

Made in the USA