The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is the mechanical heart of the world’s most renowned progressive reloading systems. Engineered to provide seamless, high-speed dispensing without sacrificing the meticulous accuracy required for precision shooting, this assembly is a masterclass in industrial design. Unlike standalone manual measures that require a separate operation, the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is integrated directly into the press cycle, utilizing the upward movement of the ram to trigger a precise volumetric drop of propellant. This “case-activated” philosophy ensures that powder is only dispensed when a cartridge case is present at the station, effectively eliminating the risk of double-charges or messy spills that can halt a high-volume reloading session.
For the modern reloader, time is the most valuable resource. The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is designed to maximize this resource by facilitating loading rates of 500 to over 800 rounds per hour, depending on the machine it is paired with. Whether you are prepping hundreds of rounds for a weekend competition in 308 Winchester or precision loading varmint rounds in 223 Remington, this assembly provides the repeatable performance and safety margins necessary for peace of mind at the bench. Its robust construction and simple, failsafe mechanical linkage have made it the industry standard by which all other progressive powder systems are measured.
- Tool Category – Automated Volumetric Powder Measure for Progressive Presses
- Operation Type – Case-activated mechanical slide-bar system
- Mechanical Standout – Positive-return failsafe rod system that mechanically resets the powder bar to prevent “bridging” or missed charges
Best For: The high-volume progressive reloader using a Dillon RL550C or Dillon XL 750 who demands a “set it and forget it” powder system capable of +/- 0.1-grain consistency with ball and fine flake powders.
Technical Specifications & Market Pricing
The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 utilizes a horizontal sliding bar mechanism rather than the rotating drums found in many competitor models. This design allows for a very low-profile fit on a crowded toolhead and provides a direct, vertical drop path into the case mouth.
| Field | Value |
| Model | Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 |
| MPN | 20782 |
| Materials | Cast aluminum body, steel slide bars, high-strength polymer reservoir |
| Weight (lbs) | 1.8 lbs |
| MSRP | $149.00 |
| Approx. Street Price | $149.00 |
Pricing Analysis
Dillon Precision maintains very tight control over its pricing and distribution network, which means the MSRP and “Street Price” are almost always identical. While $149.00 may seem high compared to a budget-oriented Lee Deluxe Auto-Drum Powder Measure, the price includes both the “Small” and “Large” powder bars, allowing the user to load everything from small pistol charges to large magnum rifle loads out of the box. The “blue” premium is also a reflection of the legendary “No-B.S.” lifetime warranty, which ensures that any component – from the clear reservoir to the intricate linkage – will be replaced by Dillon if it ever fails under normal use. In a market where digital dispensers like the RCBS ChargeMaster Supreme Digital Powder Scale and Dispenser can cost over $400.00, the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 offers a mechanical solution that is faster, requires no electricity, and is nearly as accurate for the vast majority of shooting disciplines.
Build Quality, Materials, and Ergonomics
The build quality of the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is built around a heavy-duty cast aluminum body that is finished in Dillon’s signature blue powder coat. This body serves as a stable platform for the steel slide bars, which are ground to tight tolerances to ensure they glide smoothly without leaking fine ball powders like Winchester 231 or Hodgdon H335.
Material Science and Static Control
The reservoir of the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is made from a clear, high-impact polymer that allows the reloader to monitor powder levels at a glance. However, polymer reservoirs are prone to static electricity, which can cause powder kernels to “cling” to the walls and affect the consistency of the volumetric drop. Dillon mitigates this by providing high-quality internal surfaces, but many experts recommend wiping the interior with a used dryer sheet to neutralize charges. The linkage parts are constructed from a combination of stamped and machined steel, providing the “mechanical advantage” needed to shear through occasional long-grain extruded powder kernels, such as IMR 4064 or Hodgdon Varget, without jamming the press.
Ergonomics of Adjustment
Adjusting the charge on the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is accomplished via a 7/16-inch hex bolt located on the end of the powder bar. While some reloaders find the need for a wrench to be a slight ergonomic drawback, this design ensures that once a charge weight is set, it is mechanically locked and cannot “drift” during a long reloading session. The leverage provided by the press handle translates into a smooth, rhythmic clunk-clunk sound as the bar travels forward to pick up powder and backward to drop it. This auditory feedback is a key ergonomic feature, allowing the user to hear that the system is cycling correctly without constantly looking up at the measure.
Comprehensive Setup, Calibration, and Operation
Successful integration of the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 requires attention to detail during the initial toolhead setup.
Step-by-Step Assembly and Calibration
- Powder Die Installation: The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 must be mounted into a dedicated Dillon Powder Die. Screw the die into the toolhead of your Dillon XL 750 or Dillon RL550C.
- Adjusting for Stroke: With a resized and primed case in the station, lower the ram. Adjust the height of the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 until the powder bar travels its full length, stopping just as it becomes flush with the measure body. This ensures the volumetric cavity is perfectly aligned for a full drop.
- The Failsafe Rod: This is a critical safety step. Connect the white plastic wing nut and failsafe rod from the measure’s bellcrank to the bracket on the press frame. The spring should be slightly compressed at the bottom of the stroke. This rod mechanically “yanks” the powder bar back to the starting position as the ram is lowered, preventing a “stuck” bar that could lead to a missed charge.
- Selecting the Bar: For small charges (under 20 grains) like those used with Alliant Unique in pistol calibers, use the Small bar. For rifle charges (up to 50-60 grains), use the Large bar.
- Verifying the Charge: Fill the hopper with powder, such as Hodgdon H4350. Throw 10-15 “dummy” charges to allow the powder to settle. Then, weigh ten individual drops on a scale like the Dillon Precision D-Terminator Electronic Powder Scale 1500 Grain Capacity to calculate your average and ensure you are hitting your target weight.
Maintenance and Cleaning
The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 is a low-maintenance tool, but it should be cleaned every few thousand rounds. Use a soft brush to remove powder dust from the slide bar channels. Never use liquid lubricants or oils on the powder bar, as this will cause powder to clump and lead to dangerous charge variations. If the bar becomes “sticky,” a light application of dry powdered graphite is the only recommended treatment.
Internal Brand Hierarchy
Dillon offers several variations of their powder systems, each tailored to specific machine architectures.
- Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750: The standard, most versatile model compatible with the most popular homeowner presses.
- Dillon Precision Powder Measure Assembly Square Deal B: A specialized, smaller version dedicated solely to the Square Deal B pistol press.
- Dillon Precision Powder Measure 1050, RL1100: A high-speed variant for the commercial-grade Dillon RL 1100 and Super 1050 machines, featuring a different linkage for the longer stroke and eccentric movement of those presses.
- Dillon Precision Belted Magnum Powder Measure RL550, XL650, BL550: Designed with an Extra Large powder bar for the massive propellant charges required for cartridges like 300 Weatherby Magnum or 338 Lapua Magnum.
Competitive Market Analysis
The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 exists in a competitive landscape where other brands attempt to replicate Dillon’s success with varying results.
Deep Dive into Competitors
- Hornady Lock-N-Load Powder Measure: This is a drum-style measure. While it is arguably more consistent with long-grain extruded powders because the drum “cuts” the kernels more cleanly than a sliding bar, it is also much bulkier and can be harder to adjust for small pistol charges without purchasing separate rotors.
- Lee Deluxe Auto-Drum Powder Measure: The budget champion. It utilizes elastomer wipers to prevent leaking with fine powders. While highly accurate, the build quality is significantly lower than the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750, and it lacks the positive mechanical failsafe rod system.
- RCBS Uniflow Powder Measure 3: A legendary manual measure that can be converted to case-activated use with an optional kit. It offers excellent precision but lacks the integrated “Dillon Blue” workflow and compact profile of the native Dillon assembly.
- Frankford Arsenal Progressive Press Case Activated Powder Measure: A modern take on the case-activated system. It features a very large reservoir and a built-in baffle. It is a strong competitor for those not already committed to the Dillon ecosystem, though it lacks the “lifetime” brand pedigree of the blue machine.
Comparison Table
| Feature | Dillon Assembly | Hornady L-N-L | Lee Auto-Drum | RCBS Uniflow 3 |
| Mechanism | Sliding Bar | Rotating Drum | Rotating Drum | Rotating Drum |
| Reset System | Failsafe Rod | Spring Return | Internal Gear | Spring Return |
| Max Capacity | ~60 Grains (Large) | ~100 Grains | ~80 Grains | ~100 Grains |
| Warranty | Lifetime (No B.S.) | Limited | Limited | Limited |
Real-World Feedback & Troubleshooting
Experienced reloaders who run the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 for cartridges like 6.5 Creedmoor or 30-06 Springfield often note that the system’s accuracy is heavily dependent on the “rhythm” of the operator.
Pros
- Extremely fast; the bottleneck of the press cycle is rarely the powder drop.
- “Case-activated” feature is a massive safety upgrade over manual measures.
- Includes multiple bars for total caliber versatility.
Cons
- Struggles with very long stick powders, occasionally varying by 0.3-0.5 grains.
- Hex-head adjustment bolt is less convenient than a micrometer dial.
Troubleshooting: 3 Technical Quirks
- The “Clunk” Noise: If the measure makes a loud metallic clunk, it usually means the failsafe rod is set too tight. Expert Workaround: Loosen the white wing nut until the rod has just a tiny amount of “play” at the bottom of the ram stroke.
- Powder Spillage: This often happens when the case is flared too much. Ensure your powder funnel is only “belling” the case mouth just enough to accept a bullet. Excessive belling creates a “pop” as the case exits the powder die, flinging fine grains of Winchester 231 across the shellplate.
- Static Cling: If the powder levels look uneven or powder is sticking to the hopper walls, ground your press. Attach a copper wire from one of the mounting bolts of your Dillon XL 750 to a metal water pipe or a dedicated grounding rod.
FAQ
Q: Can I use the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 with a single-stage press?
A: Not directly. It is designed for the automatic indexing and specialized toolheads of Dillon progressive presses. For a single-stage, a manual Hornady Lock-N-Load Powder Measure is more appropriate.
Q: Is there a way to add a micrometer adjustment?
A: While Dillon does not sell one, several aftermarket companies make “micrometer knobs” that press onto the existing hex bolt of the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750.
Q: Will it work with Hodgdon Varget?
A: Yes, but with a caveat. For precision match ammo, most reloaders find the sliding bar can “crunch” the long kernels of Hodgdon Varget, leading to slightly larger weight variations than ball powders.
Q: How do I change powders quickly?
A: Simply pull the two pins that hold the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 to the powder die, remove the assembly, and dump the hopper back into your powder bottle.
Q: What is the purpose of the “Extra Small” powder bar?
A: It is a separate accessory for dropping extremely small charges (under 3 grains) for tiny cartridges like 32 Auto or 25 ACP where the standard Small bar might be inconsistent.
Q: Do I need a powder baffle?
A: Many reloaders find that adding an aftermarket baffle to the Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 helps maintain consistent downward pressure as the reservoir empties, improving accuracy.
Q: Can the measure be used for black powder?
A: No. Smokeless powder measures are not designed for the spark-sensitivity and corrosive nature of black powder.
Conclusion & Expert Verdict
The Dillon Precision Case Activated Powder Measure Assembly RL550, XL650, XL750 remains the gold standard for progressive reloading for a reason. Its simplicity is its strength; by using a direct mechanical linkage and a robust sliding bar, Dillon has created a system that is as close to “bulletproof” as possible in the reloading world. While it may require a little extra attention when using extruded rifle powders, its performance with ball and flake powders is unmatched in the progressive category. For anyone serious about high-volume reloading, this assembly is not just a tool – it is an investment in a lifetime of precision shooting.
Expert Pro Tip: To achieve the absolute best consistency, implement a “3-second dwell” at the top of every stroke. This allows the powder kernels enough time to fully fall through the narrow powder funnel and into the case, particularly when using bulky powders for cartridges like 308 Winchester.
