Fluted Bullets: The Future of Handgun Ammunition? By: Dr. Martin D. Topper

Fluted 12 Water Melon shot with .45 Polycase ARX

Extreme Defense and 9mm. Polycase +P

There hasn’t been a radically new type of handgun bullet loaded in factory ammunition since the Super Vel jacketed hollow-point appeared in the late 1960s.  Today we have four companies loading fluted bullets, and early reports from the shooting range, ballistic laboratory and hunting fields indicate that fluted handgun bullets appear to produce desirable tactical penetration and large temporary and permanent cavities at handgun velocities.  As such, cartridges loaded with them are clearly candidates for being classified as 5th Generation Hyper-Efficient ammunition.


Fluted Bullet 3 Rounds Reviewed for this Article

The fluted bullet was first experimented with about 20 years ago. That projectile was made of sintered metal and had five flutes in its nose.  It was developed by Charles Kelsey with help from bullet designer Tom Burcyznski, but sufficient funds weren’t available to bring Kelsey’s “Devel” bullet into production.  In the last five years, two companies, Polycase and Lehigh Defense, have produced different fluted bullets that are loaded in ammunition by four different companies. The first bullet is a three-flute design made of an ultra-modern injection molded polymer/copper blend.  It is manufactured by Polycase and sold under the Polycase ARX and Ruger ARX labels. This bullet was designed by Juan Carlos Marin in Spain.  The second bullet is Lehigh’s all-copper four-flute projectile.  It’s used in Underwood Ammunition, Black Hills Ammunition and Lehigh Defense Ammunition.


The theory behind fluted bullets is that the flutes accelerate body fluids and direct them laterally to expend energy in a way that damages tissues along the wound track and creates large (for handgun loads) temporary cavities.  (EDITOR’S NOTE: That is consistent with the fact that water – the majority or what is in a body – is non-compressible and very destructive when encountering tissue while moving rapidly.)  As the bullet continues to penetrate and loses energy, the bullet begins to tumble in a “helical” pattern and penetrates straight to a depth of between 12 and 15.5 inches, depending upon caliber.  The following video of Polycase performance does a good job of describing this process: https://www.youtube.com/watch?v=IdkDbpOntns#t=431.950558.  The same bullet behavior in gelatin was seen with the five flute Devel bullet. The Polycase and Lehigh bullets are constructed of relatively lightweight materials, so their velocities are quite high as are their energy levels.

Shots Fired

Polycase .45 wound channel in Ballistic Gel

Several sessions at the range over the past year with Polycase, and Underwood and ammunition have shown me that fluted bullets perform as predicted.  The bullets do indeed penetrate nose-on for a distance and then rotate as they tumble, often ending up base first in the gelatin.  Direction of penetration is quite straight and somewhat deeper than a hollowpoint bullet of the same caliber.  The permanent wound channel in the gelatin is also somewhat larger than a hollowpoint of the same caliber.  The following web site has a video that demonstrates the performance of Polycase ARX bullets well:https://www.dropbox.com/s/r0uq45mx3568w8w/Polycase%20Media%20Day.mp4?dl=0. 

Author firing Luger, known for being selective for the ammo it can digest using Polycase 9mm. +P

Terminal effects of the bullets fired in this video closely match results I’ve seen in gelatin effects and also match photographs of fluted bullet performance in wild hogs. The fluted bullets were also quite accurate when fired at common tactical distances.  With semi-autos the fluted bullets shot very close to the point of aim at seven and ten yards and groups were quite small. When firing Polycase ammo in revolvers, the distance from point of aim to point of impact was somewhat greater, which is something I’ve also noticed when firing jacketed hollowpoints of different weights in the same wheelgun.  As for reliability, the rounded ogive of the Polycase bullets made them feed extremely well in a Luger which is notorious for jamming when hollowpoints are used.  Therefore, the Polycase bullets may be especially appropriate for semi-autos that have not been throated to feed JHP ammunition.

Bullets of the Future?

It’s too early to tell if fluted bullets are the wave of the future for handguns.  On the other hand, both Polycase and Underwood Ammunition report good sales, so their future presently looks quite bright.

Factory Ballistics*:


Bullet Weight


Muzzle Velocity

(feet per second)

Muzzle Energy


Black Hills .38 Spl.Xtreme Defense +P 100 grs. 1275 fps 361 ft. lbm.
Black Hills .380 ACP Xtreme Defense 60 grs. 1150 fps 176 ft. lbm.
Polycase .38 Spl. ARX 77 grs. 1116 fps. 213 ft. ibm.
Polycase 9mm. +P 80 grs. 1445 fps. 371 ft. lbm.


Underwood 9mm. Xtreme Defender 90 gr. 1400 fps. 392 ft. lbm.
Under Wood .45 ACP Xtreme Penetrator 200 gr. 1000 fps. 444 ft. lbm.

* These are just six of the available loads with fluted bullets.  Go to www.black-hills.com, www.polycaseammo.com, www.lehighdefense.com, or www.underwoodammo.com for a complete listing.

1 Comment on "Fluted Bullets: The Future of Handgun Ammunition? By: Dr. Martin D. Topper"

  1. Devel also produced a 175 grain .45 caliber copper solid bullet that was saboted for .50 caliber muzzle loaders. It was the most accurate bullet out of my Savage ML-10. Wish it was still in production

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