Why Rimless Cartridges?

Here's the long answer to that question, including some interesting background to consider especially with respect to the shotgun and shotshell industry.

Springfield Armory started the rimless revolution in rifles with the .30-'06 cartridge, which supported such innovative designs as the M1903 rifle, the BAR, and the M1 Garand.  Meanwhile, John Browning kept that revolution going in handguns with his classic Model 1911 pistol and the .45 ACP cartridge.  Not to mention thereafter his groundbreaking Hi-Power pistol in 9mm Luger.

Why this evolution?  The firearms industry saw the need for cartridges designed specifically for box magazine fed firearms, and especially those firearms with autoloading actions.  Browning, Luger, Garand, Stoner, Glock - these various men answered the call with their now legendary and enduring cartridge and firearm designs throughout the 20th century.

Rifles and pistols to this day have benefited enormously as a result.  In particular, rimless cartridges allow for capture style bolts and plunger style ejectors - design elements which have greatly benefited modern mag fed rifle platforms in particular.  Rimless ammo also tends to reduce gun parts count, enables much simpler magazine designs, and provides superior stacking in vertical configurations.  These features combine to allow for more flawless cartridge feeding, extraction, and ejection.

All of these advantages were only made possible with rimless cartridges.

However, the rimless revolution never occurred in shotguns.  The shotshell cartridge remained stuck in its original rimmed form factor, and the only real major shotshell hull innovation over the last 100 years has been the use of plastics to replace rolled paper in the tube and basewad of the hull.

The shotshell hull itself today is a somewhat complex combination of typically three different plastic and metal materials.  The manufacturing processes for these hulls require specialized and intricate extrusion, stamping, and cold forming tooling and equipment lines.  High setup costs, high maintenance requirements.

The hard truth is that rimmed cartridges originally developed in the mid to late 19th century were never designed for use in box mag fed autoloading firearms because these platforms simply did not exist yet!  Although the need for progress was recognized and addressed in rifles and pistols, the industry did not respond accordingly for shotguns.  Thus the shotshell ammunition and shotgun firearm world has been held back accordingly ever since.

Until now.

Detac Arms LLC is proud to introduce a truly overdue solution - the B-MAG rimless shotshell cartridge.  Featuring the world's first all polymer (no metal material needed) injection molded 12ga shotshell hull that utilizes existing 12ga components and loading processes.  Designed for both folded and rolled existing crimping methods.  With a proper, robust extraction rim for intense autoloading environments.  A belted forward rim for positive headspacing.  And, an overall base design optimized for use in capture bolts with a single extractor and a plunger ejector - eliminating the need for a fixed ejector independent of the bolt or the need for dual extractors.  Tested per current SAAMI Z299.2 velocity and pressure testing procedures to meet or exceed existing rimmed 12ga standards for performance.  Offered in a variety of hard hitting lead and tungsten loads for hunting, sporting, home defense, and tactical (Mil / LE) applications.

Detac is also proud to introduce the RS-10 model shotgun - a true AR platform magazine fed firearm that brings the entire AR10/15 parts and accessories aftermarket into play with the shotgun world.  The RS-10 features a simple and lightweight injection molded 8 round detachable magazine, along with an upper receiver assembly that uses the same design charging handle, bolt carrier, and direct impingement gas system as its most common rifle counterparts.  In fact, the RS-10 can be switched in seconds from a shotgun to a rifle by simply swapping the upper receiver assembly and the magazine back and forth on the true AR10 style (DPMS Stoner Gen1 pattern) lower receiver assembly.

The time has finally arrived.  The 1800's just called and they want all of their old rimmed shotgun stuff back!

We are Detac Arms LLC, leaders of the rimless shotshell revolution.  We invite you to explore how you - as gun owners, dealers, distributors, and manufacturers - can join the revolution too!