Engineers’ perspective on the Remington 700 VTR triangular barrel

    CR Riddell, PE posted a comment about the Remington 700 VTR triangular barrel and I thought it deserved its own blog post:

    I am a professional structural engineer. In 1977, I was granted a patent on a structural system that uses triangular cross-section members with a circular cross-section hole down the middle. Remington’s VTR barrel is identical to that shape. The objective of this shape is to maximize structural force transmission with a minimum of mass.

    700 Vtr Muzzlebreak-1
    Remington Model 700 VTR barrel and integral muzzle brake.

    During development of the concept, I established that the triangular cross-section provides the maximum surface area for a given enclosed volume. This accounts for the Remington heat dissipation claim/feature. Removing the mass along the central axis leaves the mass in the three corners at a maximum distance from the central axis. This maximizes the axial compression rigidity and the torsional rigidity, also a Remington claim/feature. The torsional rigidity promotes stability under the influence of the rifling twist, a special benefit in a rifle barrel. Flexural stiffness is optimal for downward bending of the muzzle end in the orientation Remington uses in the stock; one corner up and two corners down. That puts the top corner in tension and the bottom corners in compression, where buckling concerns reduce the allowable load-carrying capacity.

    Picture 4-26
    From Riddell’s Structural Member and System patent (#4007574)

    All this techno-mumb-jumbo counts for doodly, unless the holes in the target get chummy and cuddle up together. As with all accuracy discussions, the teamwork between barrel, bedding, and ammo gives a unique performance result. This must be where Remington spent its advertised years in development.

    Obviously, the manufacturer cannot control the customer’s choice of rounds, so they have to shoot for a statistical middle, so to speak. But the bedding is another story. Remington advertises a multi-point mount, not free-floating or glass bedding. This would be crucial for taming the harmonics in concert with the unique tension-vs-compression qualities of the barrel shape.

    Thoretically, this barrel should be better than round, but the industrial wisdom and inertia is all compiled for round. Some tuning is required.

    Very interesting. Thanks CR for the information.

    Steve Johnson

    I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!