The Forster Co-Ax Bench Priming Tool represents the pinnacle of dedicated priming engineering, designed for the reloader who demands absolute precision and tactile feedback without the inherent fatigue of handheld units. In the sequence of precision reloading, primer seating is often underestimated; however, the depth and squareness of a primer can be the difference between a record-breaking group and a frustrating misfire. The Forster Co-Ax Bench Priming Tool addresses these variables through a unique coaxial design that ensures primers are seated perfectly flat and to a consistent depth every single time. Originally developed under the Bonanza brand, this tool has become a staple for long-range competitors and benchrest shooters who require a “feel” for the primer pocket that progressive presses and even many single-stage presses simply cannot provide.
Unlike most priming systems that rely on individual shellholders, the Forster Co-Ax Bench Priming Tool utilizes a sophisticated integrated jaw system. This universal approach allows the reloader to move between different cartridges – from 223 Remington to 30-06 Springfield—with minimal mechanical adjustment. The tool is designed to mount securely to a bench, providing a stable platform that uses mechanical leverage to seat primers with a slow, steady pressure. This controlled movement is critical for preventing the crushing of primer pellets, an issue often encountered with high-speed or less refined tools.
- Tool Category – Bench-Mounted Priming Station
- Operation Type – Manual Lever-Action with Universal Jaws
- Mechanical Standout – Primers stack sideways in feed tubes for maximum safety
Best For: Precision rifle shooters and high-volume reloaders who suffer from hand fatigue with manual tools but require more consistency and “feel” than what is offered by press-mounted priming systems.
Technical Specifications & Market Pricing
The Forster Co-Ax Bench Priming Tool is built to exacting tolerances in the United States, utilizing high-grade aluminum and tool steel to ensure a lifetime of service. The following specifications detail the core metrics of the current production model.
| Field | Value |
| Model | Forster Co-Ax Bench Priming Tool |
| MPN | 011521 |
| Materials | Machined Aluminum Base Casting / Hardened Tool Steel Jaws |
| Weight (lbs) | 1.54 lbs (0.7 kg) |
| MSRP | $187.00 |
| Approx. Street Price | $124.99-142.99 |
Pricing Analysis
The Forster Co-Ax Bench Priming Tool occupies the premium tier of the bench-mounted market. While its MSRP is positioned near $187, savvy reloaders can typically find it at major retailers for approximately $130. While this is significantly more expensive than a budget-friendly Lee Auto Bench Priming Tool, the investment is justified by the universal jaw system. Traditional priming tools require the purchase of specific shellholders for every caliber family, which can quickly add $50-100 to the total cost for a multi-caliber reloader. By eliminating the need for these accessories, the Forster Co-Ax Bench Priming Tool provides a higher value proposition over the long term. Furthermore, the tool’s robust construction and the fact that it is backed by Forster’s lifetime warranty against defects in materials and workmanship make it a “buy once, cry once” piece of equipment for the serious enthusiast.
Build Quality, Materials, and Ergonomics
The construction of the Forster Co-Ax Bench Priming Tool reflects the same industrial-grade philosophy found in the famous Forster Co-Ax Press. The foundation is a high-quality machined aluminum casting that provides a rigid, non-flexing base for the priming operation. Rigidity is essential in a priming tool; any flex in the handle or base absorbs the “feel” that the reloader needs to determine when a primer has bottomed out in the pocket.
Material Integrity
The internal components, specifically the E-Z Just shellholder jaws and the primer seating posts, are manufactured from hardened tool steel. This is a critical distinction, as these parts are under constant pressure and friction. The use of steel for the jaws ensures that they do not stretch or wear down even after processing tens of thousands of cases of 308 Winchester or heavy-recoil magnum cartridges. The primer feed tubes are also constructed from aluminum rather than the plastic found on cheaper competitors, offering better protection for the primers and a smoother feed path.
Ergonomics and Tactile Feedback
Ergonomically, the Forster Co-Ax Bench Priming Tool is designed for a natural, downward-stroke operation. The lever is purposefully shorter than a standard reloading press handle, which is a deliberate engineering choice. A longer lever would provide too much mechanical advantage, potentially allowing a reloader to crush a primer without realizing it. The shorter lever on the Forster Co-Ax Bench Priming Tool preserves the tactile feedback, allowing the user to feel the exact moment the primer makes contact with the bottom of the pocket. This allows for seating primers consistently at 0.003-0.005 inches below flush, which is the standard for reliable ignition in precision rifles.
Comprehensive Setup, Calibration, and Operation
Setting up the Forster Co-Ax Bench Priming Tool is a one-time process that, once mastered, allows for rapid transitions between calibers.
Mounting Instructions
The Forster Co-Ax Bench Priming Tool features a base with pre-drilled holes for mounting. It is highly recommended to bolt this tool directly to a stable reloading bench using 1/4 inch lag bolts. However, for those with limited space, many users mount the tool to a small wooden block or an aluminum plate which can then be clamped into a vise or an RCBS Automatic Bench Priming Tool mount system.
Adjusting the E-Z Just Jaws
The “heart” of the Forster Co-Ax Bench Priming Tool is the three-jaw system. To calibrate the jaws for a specific case, such as 223 Remington, follow these steps:
- Loosen the three socket head cap screws on the jaw housing.
- Insert a deprimed and resized case into the center of the tool.
- Depress the handle slightly to raise the primer seating post into the pocket of the case.
- Snug the jaws around the rim of the case. They should be tight enough to hold the case squarely but loose enough to allow the case to be slid in and out easily.
- Tighten the screws to lock the jaws in place. This setting will now work for any cartridge sharing that rim diameter, such as 22-250 Remington or 6mm ARC.
Safety and Feeding
The Forster Co-Ax Bench Priming Tool utilizes a unique safety feature: primers stack sideways in the feed tubes. This ensures that if a primer were to detonate, the energy would be directed outward through the slot in the tube rather than upwards in a chain reaction. To fill the tubes, simply place your primers (like CCI 200 or Federal GM210M) into the built-in primer flip tray, shake them until they are right-side up, and slide them into the tube.
Internal Brand Hierarchy
Forster Products offers two primary ways to seat primers: the built-in system on the Co-Ax Press and the standalone Forster Co-Ax Bench Priming Tool. While both are high-quality, they serve different purposes. The built-in primer on the press is a single-feed system, meaning you must place one primer at a time into the tool. This is excellent for ultra-precise, low-volume loading of match ammunition for calibers like 6.5 Creedmoor.
However, for a reloader processing 100-500 rounds of 45 ACP or 5.56 NATO, the built-in press primer is too slow. The Forster Co-Ax Bench Priming Tool acts as the high-speed upgrade. It maintains the same precision as the press-mounted version but adds the efficiency of a tube-feed system. For the reloader who already owns the Forster Co-Ax Press, adding the Forster Co-Ax Bench Priming Tool completes the workflow, allowing for bulk preparation of brass while reserving the press for sizing and bullet seating.
Competitive Market Analysis
The market for bench-mounted priming tools is competitive, with several manufacturers offering distinct advantages. The Forster Co-Ax Bench Priming Tool competes primarily with the following four tools:
- RCBS Automatic Bench Priming Tool: This is arguably the closest rival. The RCBS uses traditional shellholders and a large-capacity primer tray. While it is faster for long production runs, many reloaders find that it lacks the “surgical” feel of the Forster Co-Ax Bench Priming Tool.
- Hornady Versa-Prime Bench Priming Tool: Hornady’s offering focuses on speed and ease of primer loading. It is a solid mid-range choice, but it uses more plastic components compared to the all-metal construction of the Forster.
- Lyman Accu-Prime Auto-Load Bench Priming Tool: The Lyman tool is a budget-conscious alternative. It performs well for general reloading but does not offer the same level of coaxial alignment as the Forster Co-Ax Bench Priming Tool.
- Lee Auto Bench Priming Tool: The Lee tool is the most affordable in the category. It is highly functional and uses a unique triangular tray, but it lacks the heavy-duty build quality and lifetime durability of the Forster unit.
Comparison Table: Bench Priming Tools
| Tool | Materials | Feed System | Shellholder Type | Price Class |
| Forster Co-Ax Bench Priming Tool | Aluminum & Steel | Sideways Tube | Universal Jaws | Premium |
| RCBS Automatic Bench Priming Tool | Cast Iron & Steel | Vertical Tube | Standard | Mid-Premium |
| Hornady Versa-Prime | Alloy & Plastic | Tray Feed | Standard | Mid-Range |
| Lee Auto Bench Priming | Zinc & Plastic | Tray Feed | Special Lee | Budget |
Real-World Feedback & Troubleshooting
Reloader feedback on the Forster Co-Ax Bench Priming Tool highlights its incredible consistency. Users frequently report that “high primers” (primers that sit above the case head) are virtually eliminated once the tool is set up. This is vital for safety in semi-automatic rifles like the AR-15 chambered in 223 Remington, where a high primer can cause a slam-fire.
Common Troubleshooting Issues
- Gritty Feeling during Seating: This is often caused by brass shavings or primer pocket residue falling into the jaw housing. Solution: Periodically disassemble the jaws and clean them with a brush and a light solvent.
- Primers Not Feeding: If primers get stuck in the tube, ensure the tube is clean and free of oil. Primers are light, and even a small amount of oil can cause them to stick. Solution: Clean the interior of the tubes with a dry patch.
- Difficulty Swapping Primer Sizes: Moving from large to small primers requires swapping the internal seater assembly. Solution: Always center the jaws before moving the assembly forward; this ensures the new seating post aligns perfectly with the case head.
FAQ (Extended)
Q: Can the Forster Co-Ax Bench Priming Tool handle 50 BMG cases?
A: No, the jaws are designed for standard modern rifle and pistol cases. For 50 BMG, a specialized heavy-duty priming unit is required.
Q: Do I need to buy special shellholders for this tool?
A: No, the E-Z Just jaws are universal and can be adjusted to fit almost any rim diameter from 25 ACP up to many magnum rifle cartridges.
Q: How many primers do the tubes hold?
A: The Small primer tube holds 41 primers, and the Large primer tube holds 52 primers.
Q: Is it safe to use this tool with magnum primers?
A: Yes, it is fully compatible with magnum primers like CCI 250 or Winchester WLRM. The sideways stacking tube design adds an extra layer of safety.
Q: Can I use this tool for 45 ACP cases with small primer pockets?
A: Yes, you simply install the Small primer seater assembly and adjust the jaws to the 45 ACP rim diameter.
Q: Does the tool come with both Large and Small primer assemblies?
A: Yes, the Forster Co-Ax Bench Priming Tool includes everything needed to prime both Large and Small primer sizes.
Q: How do I know if the primer is seated deep enough?
A: You will feel a positive “stop” when the primer hits the bottom of the pocket. For precision work, use a depth gauge to ensure it is 0.003-0.005 inches below flush.
Q: Can I mount this tool to an Inline Fabrication mount?
A: Yes, Inline Fabrication makes specific top plates that allow the Forster Co-Ax Bench Priming Tool to be used with their Quick Change system.
Conclusion & Expert Verdict
The Forster Co-Ax Bench Priming Tool is an essential instrument for the reloader who views priming as a critical step in the precision chain rather than a mundane chore. Its hallmark is the perfect balance between mechanical efficiency and tactile feedback. By utilizing a bench-mounted design, it eliminates the physical strain of handheld tools while providing a level of coaxial alignment that is difficult to achieve on a standard reloading press. While the initial cost and the slight learning curve of the universal jaws may deter some beginners, the long-term benefits of consistent ignition and professional-grade durability are undeniable.
Expert Pro Tip: When loading the primer tubes using the built-in tray, use a straightened paper clip to hold the primers in the tube while you transfer it to the tool. This prevents the primers from sliding out of the open slot and ensures a clean, hassle-free setup every time. Also, always sort your brass by headstamp before priming, as different manufacturers like Winchester or Norma may have slight variations in pocket depth that you will be able to “feel” through the handle.
