Recently, popularity has been growing behind a previous rendition of military/firearm history—the entry stock. While many civilian companies have attempted to duplicate this classic look, Joy Engineering (JE) Group has recently been working on a prototype that could potentially reestablish the former design.

As a brief back history, during the initial Gulf War the challenges of full-length A2 buttstocks on the M16A4 platform were noted as problematic in urban environments. Canada had previously attempted to address this with its “CS” short stock in its C7 program that was approximately one inche less in overall length than the A2. However, law enforcement had an increasing need in the 90s and early 2000s for more urban-centric firearms, so Colt and other manufacturers continued to seek out methods to shorten the AR platform.

Circa 2010, Rock River Arms introduced its “entry stock” as an after-market reproduction to the classic milspec version, and an effort to blend the sturdiness of the A2 with the compact length of a carbine stock . However by 2020 it discontinued these due to slumping sales. Leapers, Double Star, and Model 1 also reproduced the design under different names (such as “Tactical Entry Stock”), but similarly discontinued these later. Many garage-based shops have attempted to cut A2 stocks down to entry stock length, but often those efforts never keep pace with demand.

Beginning in 2021, and recognizing the continued market demand for an entry-style stock, JE owner Adam Avila began experimenting with different methods of 3D printing. His intent was to develop a fixed carbine (total length 7.7”), an A5 (total length 8.7”) stock, or a “modified rifle” (total length 9.7”) that was compatible with current mil-spec adjustable tubes, and has the traditional in-stock storage. His project was later named the “Sentry” stock.

The Sentry Stock is broken down into three main elements:

• Extension length: A reference to the overall length of the stock itself utilizing either:
  • A standard carbine (CAR) length buffer tube
  • An A5 Knights Armament buffer tube length with an Endplate Sling Adapter FCD – Heavy (ESF-H)
  • A “modified rifle” type that has yet to be defined
• End plate: A reference to the angular design of the stock’s end plate, and is available in:
  • Milspec with a full notch to accommodate many civilian castle nut-style AR platforms
  • ESFH-1 with a slight notch to allot for only an ESF-H but with a standard carbine length buffer tube
  • FLATwith a flush face to allot for KAC buffer tube length w/ESF-H
• Attachment method: A reference to the sling attachment style, available in either a standard three-socket quick detachment method, or the Sling Loop Modification (SLMOD) bracket that accommodate slings up to 1.25” in width or clip-on attachment points.

Thus, the designations for some of the various types of Sentry Stock designs at the time of this writing is as follows:

• JE.Sentry.CAR.MIL
• JE.Sentry.CAR.FLAT
• JE.Sentry.CAR.ESFH1
• JE.Sentry.A5.MIL
• JE.Sentry.A5.FLAT
• JE.Sentry.A5.ESFH1

The Sentry stock is available in either a black (-BLK), OD green (-ODG), or flat dark earth (-FDE) using the preferred color coding at the end of the order designation (for example a JE.Sentry.CAR.MIL-BLK). Carbine stocks themselves have an overall weight of just 11.9 ounces.

The locking mechanism that secures the Sentry stock to the lower receiver is an internal locking sled nut that requires 40lb for complete lock up and eliminates any gaps between components.

The storage well inside the Sentry stock is designed for a watertight insert that can be interchanged as desired. The back plate is also printed and includes a spring-loaded door for easy access.

Disclaimer: The purpose of this editorial is strictly informational, much like our tourniquet, COVID Chronicles, body armor, or gear guide, this series is not intended by High Ground to sway or convince the reader that one specific brand of accessory is superior to all the others. In the end, this article is intended to provide the reader with a condensed and focused resource—nothing more.

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