New: The OATH 12ga TSR Slug

The all-copper slug is a wasp-waisted hollow point massing 602 grains, or just over 1 1/3oz. Extensive machining allows it to expand almost immediately after impacting wet media like flesh with minimal expenditure of the available kinetic energy for deformation. Loaded in a 2.75″ inch case, the slug moves at moderate 1200fps and so kicks no more than a heavy game load. The lightweight case is precision machined from billet aerospace grade aluminum, so it’s slicker than regular plastic hulls for easier extraction and far more durable, especially when loaded into box magazines. It will not deform out of round over time under spring pressure. That makes this load ideal for Vepr, Saiga and MKA1919 shotguns.

The TSR slug uses polymer driving bands to reduce chamber pressure. The wasp-waisted slug shows excellent accuracy in cylinder bore. 6″x6″x16″ gel blocks used for testing were reliably hit at 50 yards from a smoothbore shotgun. Precision manufacturing pays off in consistency.

The main feature of this projectile is the extreme degree of expansion. With the muzzle energy of 1925 foot-pounds, more than five times that of 45ACP, any normally constructed slug would blow right through the relatively soft-skinned vertical aggressor and keep on traveling through the matchstick and veneer houses typical of the American suburbia. TSR, initially .70 caliber, expands to 2.6 inches, with six sturdy, sharp petals widening the frontal area by around 460%. The hollow base becomes a ring to decrease the amount of resistance the projectile encounters in the middle: it’s not like the half-inch wide meat cylinder that will squeeze through it would remain viable tissue. All that adds up to a ragged wound channel over two and a half inches across and about a foot deep!

In the gel block photo, you can see the projectile penetrated 12 inches, then bounced back to the 9-inch mark. Since each arm of the expanded star is sharp in the front and wide in the back, the tendency of such shape to self-align with the path of least resistance keeps the slug correctly oriented while moving forward.

Compared to buckshot, it has much greater terminal effect and range. Since hydraulic pressure is required for expansion, this slug does an excellent job of defeating barriers like auto body sheet metal and glass. Compared to other slugs, it gives the widest channel into the vitals of the aggressors without much risk of over-penetration.

In about a week, I should have the test data for accuracy and compatibility with various types of autoloading shotguns. Having looked over the dozens of designs tested by OATH on their way to this design, I am quite confident that it will perform well. TSR has been in development for nearly a year, and the considerable R&D investment is showing in the results. The slugs will be sold in packs of five at $34.95, slightly more than advanced turkey loads cost. As with turkey hunting ammo, it’s unlikely that more than a handful would be required on any one occasion. TSR is now available for pre-order. It would be prudent to buy a couple-three boxes, shoot a few to function test the specific firearm, then save the rest for a special defensive occasion.