SmythBusters: Tumbling Brass with and Without Pins

Wet Tumbling Brass – Do You Really Need Stainless Steel Pins?

Hey everyone, Caleb and Steve from Brownells here! Today, we’re tackling a big question in reloading—when you wet tumble brass, do you really need stainless steel pins, or can you skip them?

There’s a lot of debate among reloaders about whether pins are necessary for cleaning brass or if they’re just an extra hassle. Some reloaders swear by them, while others argue that cleaning solution and agitation alone do the job just fine. So, we set up an experiment to put this myth to the test!

Why This Test? (Pins vs. No Pins)

This question popped up after we released our reloading series, where we demonstrated wet tumbling brass with pins. Some viewers commented that they don’t even bother using pins and still get great results.

That got us thinking: Do stainless steel pins actually make a noticeable difference?

So, today, we’re running a side-by-side test:
✔ One batch of 5.56 cases with stainless steel pins.
✔ One batch without pins.
✔ Same amount of cleaning solution, same amount of water, and same tumbling time.

At the end of the test, we’ll compare both batches and see if the pins are really worth it.

Setting Up the Experiment

To make this test as fair as possible, we’re keeping everything identical except for the pins.

✔ 50 total cases of dirty 5.56 brass.
✔ 25 cases in one tumbler WITH stainless steel pins.
✔ 25 cases in another tumbler WITHOUT pins.
✔ Same cleaning solution and water mixture.
✔ Same tumbling time (~3-4 hours).

Before tumbling, we also made sure the brass was decapped so we could evaluate how well the primer pockets get cleaned.

Adding Cleaning Solution & Water

Now that we’ve divided our brass, it’s time to prepare the tumblers.

✔ Cleaning solution added – We measured out equal amounts for each tumbler.
✔ Water added – Filled each container to the same level.
✔ Tightened the lids securely – To prevent leaks during tumbling.

With everything set and sealed, it’s time to start tumbling!

Tumbling Process & Wait Time

We placed both tumblers on the rotary tumbler machine, set them spinning, and let them run for about 3-4 hours.

During this time, we had plenty of time to chat about reloading myths, watch some brass spin around, and wait for the results.

Now, let’s see what happened!

Opening the Tumblers & First Impressions

After tumbling, it’s time to open up both batches and see what we’ve got.

✔ The water in both tumblers is filthy – A good sign that dirt and residue were removed.
✔ The batch with pins looks a bit more foamy – Possibly due to the mechanical scrubbing action of the pins.
✔ At first glance, both batches look pretty clean from the outside.

Now, let’s take a closer look at the brass itself.

Examining the Brass (Outside & Primer Pockets)

We pulled three cases from each batch and started comparing:

✔ The cases from BOTH tumblers look clean on the outside.
✔ However, the cases tumbled WITH pins have noticeably shinier necks and shoulders.
✔ The cases tumbled WITHOUT pins still have some discoloration in the primer pockets and case interiors.

At first glance, it seems like the pins made a big difference in the small details rather than overall cleanliness.

Comparing the Results Under a Borescope

To get a better look at the inside of the cases, we used a Lyman borescope.

✔ Brass tumbled WITH pins:

• The inside of the case is much cleaner.
• The primer pocket is nearly spotless, with no visible residue.
• The neck and shoulder are polished bright.

✔ Brass tumbled WITHOUT pins:

• The case interior still has noticeable fouling.
• The primer pocket has leftover carbon and debris.
• The outside looks clean, but the inside shows clear differences.

At this point, we can safely say that pins definitely help clean deep inside the cases, but do they actually affect performance?

Does It Matter for Reloading?

Here’s the big question: Does super-clean brass actually matter?

✔ If you’re just plinking at the range, probably not.
✔ If you’re handloading for extreme precision, cleaner brass could give more consistent ignition.
✔ If you’re using an automated press, clean primer pockets help with smooth priming.
✔ If you just like your brass to look perfect, pins are the way to go.

At the end of the day, clean brass is clean brass, but if you want maximum cleanliness, the pins do make a difference.

Final Thoughts – Is This Myth Busted?

So, do you need stainless steel pins for wet tumbling? No.
But do they make a noticeable difference? Absolutely.

✔ Pins provide deeper cleaning, especially inside the case and in primer pockets.
✔ If you want factory-new-looking brass, pins are worth using.
✔ If you just need functional clean brass, you can get away without them.

So, if you’re reloading for precision shooting or match ammo, pins are probably a good investment. If you’re just loading bulk range ammo, you might not need them at all.

Final Verdict: To Use Pins or Not?

✔ Use Pins If:

• You want your brass to look factory new.
• You need perfectly clean primer pockets.
• You’re reloading for precision rifle shooting.

✔ Skip Pins If:

• You just need functionally clean brass.
• You’re reloading for high-volume plinking ammo.
• You want to save time by skipping the extra step of pin separation.

So, there you have it! We did this experiment so you don’t have to.

Let Us Know What You Think!

If you have any thoughts, comments, or personal experiences, let us know!

✔ Have you noticed a big difference when using pins?
✔ Do you prefer wet tumbling without them?
✔ What’s your go-to method for cleaning brass?

Drop a comment below, and as always, if you need help with reloading questions, give us a call on the Brownells Tech Line.

Thanks for watching, and we’ll see you next time!