Review of Dillon Precision RL550B 4 Stage Progressive Reloading Press

Anyone in the reloading business will understand quality when Dillon Precision is mentioned. Dillon consistently takes reloading performance to the next level with unparalleled innovation and improvement in its reloading product line.

The Dillon Precision RL550B 4 Stage Progressive Reloading Machine is quite a mouthful to say all at once and is often referred to as the Dillon 550 in short. Dillion has been in business for over twenty years, producing reloading equipment for one type of shooter or another long enough to fill a catalog.

Dillon Precision RL550B 4 Stage Manual Progressive Reloading Press Kit

The Dillion 550 is one of the mainstays of their line and has carved and fought its way to the top to stand with brands like Hornady and Lee in the realm of excellent reloading tools. Inside the box comes many components essential to reloading fast and efficiently, including a powder measure with small and large powder bars. The small bar = 2 to 15 grains of powder. The large bar = 55 to 60 grains of powder. In addition, you can expect the following:

  • One prime system with large and small priming parts.
  • One large and one small pickup tube
  • One tool head
  • One powder die
  • One loaded cartridge catch bin
  • One written instruction manual
  • One set of standard Allen wrenches

The Dillon 550B will complete a round with each lever pull. Experienced reloaders are capable of producing upwards of 500 rounds an hour. The Dillon 550B can be set up slowly like a single stage press, allowing the reloader to make any minor adjustments to guarantee consistent reloading. Once the reloader has everything set to their guidelines, they can reload as fast as they choose. Simply due to its sheer reloading power and long standing history of success, we have no qualms about advertising this as one of the best progressive press kits available, as shown on our homepage.

Additional Features of the Dillon 550B Press

The RL550B can load rifle and pistol cartridges and uses standard 7/8 by 14 thread per inch dies, as long as they deprime in size die.

The Dillon 550B takes the efficiency of a progressive press and takes it one step further. Let’s say you have your dies set on a tool head and want to change calibers. Usually, this would mean you have to remove all your dies, replace them with the new caliber’s dies, and start the adjustment process all over again. With the Dillon 550B, you can purchase separate tool heads and convert calibers. You can switch the tool head at the drop of a hat and switch the calibers you’re reloading quickly and easily. This feature of the Dillon 550B is perfect for people in three gun competitions who choose to reload and have multiple calibers to deal with.

The Dillon 550B also has interchangeable shell heads like the tool heads. The shell head on a progressive press can hold multiple rounds of one caliber. The shell head for a 9mm with have a smaller holding platform than one for a 45 ACP, so multiple calibers require multiple shell heads. So changing the shell head is required anytime one goes from a smaller to a larger caliber or vice versa. There are exceptions; for example, 40 S&W uses the same shell head as the .357 SIG and 10 mm Automatic.

The Dillon Precision RL550B is a progressive press — so what does this mean? What’s the difference between a turret press and a progressive? A progressive press is the most efficient of all reloading presses. The machine reduces the loading time by performing multiple tasks simultaneously, all with the pull of a lever. The old joke goes, “About 500 rounds an hour.”


The speed of how fast one can reload can be dangerous if one does not follow the proper guidelines and safety when it comes to reloading. The Dillon 550B is an excellent progressive reloading press, and its only flaw is somewhat temporary or situational. A progressive press is often more complicated than a turret or single stage and has a sharper learning curve for beginners. A beginner would be much better suited for a turret press or a single stage press until they’ve mastered both protection and an understanding of how reloading works.

As a reloader, when using the Dillon 550B, I constantly check myself to make sure I am not sacrificing safety and quality for speed. The last thing you want is wasted hours when the setup is botched. That’s why you can rely on videos from YouTube to guide you in the design because nothing is made easier than watching instructions to follow step by step.

Closing Thoughts on the 550B by Dillon

Every aspect screams quality. The overall quality is the first thing people notice when unboxing the Dillon 550b Press. The press seems overbuilt and more robust than necessary. This no doubt guarantees years and years of usage.

When a company stands behind a product like this, you are undoubtedly getting a good deal. Even with the noticeable extremely high quality of the Dillon 550, they still offer the “No B.S. guarantee.” They say if it breaks, they will fix it, and that’s that. Trust me; when you start reloading with this press and see how it just oozes quality, you’ll know you won’t have to worry about ever using the warranty. You’ll still be glad it’s there, though.

The Dillon 550B is an excellent reloading press for both hobbyists and professionals, producing premium ammunition for consumers. The Dillon 4 Stage Manual Press is an ideal device built to a high quality standard and represents maximum efficiency.