Dillon Square Deal B Press Caliber Change

Dillon Square Deal B Press Caliber Change

Dillon’s Square Deal B is one of my all-time favorite presses (it better be, since I own three of them!).  Ever since demonstrating it in a previous video on progressives, I’ve received a number of questions about configuring and maintaining it from curious viewers thinking about buying one.

With that in mind, in this article I thought we could take a look at how caliber changes are performed on this model.

Let’s go ahead and get this press changed over from 357 Magnum to 38 Special.  It’s worth noting that as these cartridges both use the same shell plate, dies, locator pins and primer mechanism, we wouldn’t normally have to change those parts out.  However, for the purposes of this discussion we’re going to change them anyways, so you can get an idea of what a complete caliber change entails.


The operator begins by lowering the press handle to expose the priming tool, so they can remove the return spring.

Next, using one of the included Allen wrenches, the user removes the three bolts that attach the priming system to the press.

With the bolts gone, extracting the priming system is a snap.  The primer slide assembly, shown in the video above, is responsible for taking a primer from the magazine and aligning it with the cartridge casing’s primer pocket.  To remove it, the operator simply twists it 45 degrees, and slides it out.

There are two sizes of primer slides including a small and large, for each respective primer size.  The 38 special uses a small pistol primer, so the small slide will need to be installed.

Once again with the slide in position, the user just twists 45 degrees to lock it into place.  In the video above you will see this demonstrated from multiple angles to help clarify.

Now the operator will proceed to empty out the primer tube and magazine.  With the knurled cap removed, the user pulls the primer magazine straight out of the tube.

Even with the magazine out, there may still be some primers left inside the tube as shown above.  To remove them, the operator will dump the tube out in a suitable container.

Next, the user re-attaches the priming assembly using the three bolts, and using an allen wrench or other tool, reseats the return spring.  Finally, the primer magazine is reinserted, being careful to ensure it’s aligned with the notched end facing away from the user, and the raised edge facing towards them.

To change the tool head and dies, the operator begins by pulling the retention pin out of the powder return rod, then removing it from the powder measure.

Using an Allen wrench, the user then takes out the four bolts holding the tool head in place.

When finished, the operator will lift the tool-head free to reveal the die set.

The Square Deal B uses a proprietary die system as shown in the video above.  Excluding the case mouth flare die attached to the powder dispenser, there are also resizing, bullet seating, and bullet crimping dies.  These can be slid out easily.  Although each is numbered with the stations they should occupy, be sure to note their vertical orientation to avoid installing them upside down later.  This is also a good time to clean any bullet lube or powder that may have accumulated on them.

With the old dies gone, the operator can now can now drop the new dies into place just as easily.

Next the user takes the 38 Special tool head, and installs it over top.  The dies and powder measure are already set,  eliminating the need to perform any further configuration.  Instead, the whole unit can simply be bolted into place.

Now the operator raises the ram, and reinserts the powder return rod into the powder measure, then secures it with the retention pin.

Finally the user will need to swap out the shell plate and locator pins.  They’ll begin by removing the three brass locator pins.  Next, the operator shifts the guide rod.  Using an Allen wrench, they will remove the retention bolt holding the shell plate.

Now the operator will very slowly remove the shell plate; it’s extremely important to do this carefully as there’s a small spring applying tension to the detent ball used to align the plate.  Depending on how tense that spring is, the ball bearing can easily pop out and become lost.

With the shell plate removed, the user simply locates and places the new one in it’s place, then threads and tightens the retention bolt over top.

Next the operator takes the new locator pins for the 38 special cartridge casings and drops them into place.

Finally the user slides the guide rod back into it’s groove.

And that’s it, our caliber conversion is complete.  Other accessories such as the low primer warning system etc can of course be installed, but otherwise we’re ready to reload.


Depending on your level of technical skill that probably seems like a lot of work, but the truth is it’s actually pretty straightforward once you’ve done it a time or two.  As I mentioned earlier as well, this represents a complete conversion including the primer system and shell plate.  Any time you’re switching from similar calibers such as 38 Special and 357 Magnum, or 44 Special and 44 Magnum, the process is much quicker as you can skip those steps altogether.

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