Precision on a Progressive: 6GT on the Dillon RL-550C

It’s time to crank out some precision 6GT ammunition on a progressive! In this story, I’ll outline what to look for when loading precision ammunition on a progressive, and get a Dillon RL-550C ready to roll with 6GT.


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Dillon RL-550C: Legendary Precision and Flexibility

I recently published two stories covering progressive presses: the Progressive Press Shootout, and the Dillon Progressive Press Buyer’s Guide.

Here’s the video from our Dillon Buyer’s Guide:

And the RL-550C Overview:

I call this press the “all-rounder.” This is the third iteration of the RL 550 and is manually indexed. This allows for reloading of larger cartridges but if you aren’t used to it, you are at greater likelihood of double charging.  Overall, this simple but quality press allows for repeatable, consistent loading.

A small diameter shellplate keeps the plate from rocking, leading to more consistent shoulder bump and bullet seating depth. There is also an abundance of aftermarket accessories available for this model, including case feeders from Dillon and Double Alpha Academy and the Inline Fabrication ergonomic roller handle. This press is incredibly capable and versatile, but also more affordable than some of Dillon’s other options. With four stations and no auto-indexing, you must remember that if you want to have a powder check, for example, you’ll need to combine other steps on other stations.

As shown in the picture above:

  1. Sizing/de-priming, priming
  2. Powder charging/expansion
  3. Bullet seating
  4. Bullet crimping

What it’s for:

  • Precision progressive reloading, quality on a budget

What it’s not for:

  • Commercial or mass production reloading


  • Quality
  • Simplicity
  • Versatility, standard features
  • Precision
  • Economy


  • No auto-indexing
  • 4 stations

Powders for Progressive Precision Reloading

When selecting a powder for match-quality volume loading, consider the following:

  • Metering is a key concern
  • Ball powders meter best
  • New StaBALL powders are great option

Precision Dies

When selecting dies, there are several factors to evaluate that can affect the precision of the loaded ammunition including but not limited to:

  • Quality: body, shoulder, neck sizing areas concentric with each other and the die threads
  • Correct neck sizing area diameter
  • Sliding collar bullet seating guide

Loading Setup: 6GT

For this loading session, I opted to use the following:

The results were fantastic, and I know that this load shoots really well!

Stay tuned for additional content where we put this ammunition to the test!

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