BRI 12 gauge .500 sabot bullets.
The BRI projectile is better described as a bullet than a slug, since it more nearly resembles a bullet in both design and performance. The BRI bullet is encased in a two-piece plastic sleeve (sabot) that separates and falls away after firing, allowing the bullet to continue down range on its own. The sabot expands slightly under the force of firing, sealing the bore and centering the bullet precisely in the barrel. Bullet shape is critical, since it does not rotate, but is stabilized aerodynamically in flight. Wasp-waisted in shape, BRI bullets utilize air flow over their rear sections to achieve flight stability.
BRI bullets have over twice the sectional density of a typical shotgun slug. Sectional density of the BRI is .251, versus about .107 for a common slug. What this means is that the BRI will retain its velocity longer, and have more energy remaining at the target. In fact, at all ranges from zero to 300 yards, BRI bullets deliver more energy than a .45-70, .44 Remington Magnum, .300 Savage, .30 Remington or .30-30 Winchester--to name a few. A hard lead alloy is used for making BRI bullets that assures adequate penetration. The flattened conical tip of BRI bullets imparts maximum shock, yet contributes to good overall aerodynamic performance.
Accuracy is far superior to the typical rifled slug. One-inch groups were the norm at 50 yards from our Remington Model 1100 Slug Barrel. Many hunting rifles could do no better.
BRI claims 1,500 feet per second (fps) for their 12 Gauge/.500 bullet, so we decided to check this out on our own custom Chronograph Model 900. We found, however, that it was necessary to move the chronograph screens down range about 25 feet to keep the departing sabots away from the screens' sensitive areas. If the chrono intercepts a sabot, a false reading is assured. An instrumental velocity average of 1,228 fps was recorded. For comparison, a Federal slug was clocked at 1,378 fps, while a Remington stepped out at 1,420 fps. BRI makes a hotter load, for police use only, that registered 1,313 fps. When corrected for distance from the muzzle, chronographed results will not quite yield a muzzle velocity of 1,500 fps for the BRI bullet, but it is not too far off the mark.
Components (bullets, sabots and wads) are available for the handloader, so we just had to load up a few rounds to see how they worked. Since full investigation of pressures developed in the loads that were used has not been carried out, the author is reluctant to make specific recommendations of powder charges for BRI projectiles. We did, however, achieve velocities greater than those of loads without obvious signs of excess pressure.
An experienced reloader should have no difficulty loading BRI components. Loading is quite simple. A cardboard wad and a plastic gas-seal wad are used between powder and sabot. The loaded column is held in place by a roll crimp, which we applied with a Lyman crimping tool.
BRI 12 Gauge/.500 shells should be fired only from barrels with choked cylinder or improved cylinder, according to the manufacturer. Firing in a full choked barrel is definitely not recommended.
Loaded shells and components are available from Ballistic Research Industries, Dept. GA, 6000B Soquel Ave., Santa Cruz, CA 95062.
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|Author:||Glaze, Ralph C.|
|Publication:||Guns & Ammo|
|Date:||Jun 1, 1984|
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