An Inside Look at How AR-15 Barrels Are Made: DC Machine

DC Machine barrels
An Inside Look at How AR-15 Barrels Are Made: DC Machine

U.S.A.-(Ammoland.com)- DC Machine is the biggest machining company you may never have heard of. However, you are likely familiar with Palmetto State Armory, located in Columbia, South Carolina. PSA is one of the fastest-growing gun companies in the history of ever. While the operate a handful of retail stores, they sell lots and lots of guns and shooting gear across the country online and through other retail outlets. As it so happens, Palmetto State Armory and DC Machine are sister companies. I recently had the opportunity to tour the DC Machine operation and get a first-hand look at how quality barrels are made.

barrel stock
DC Machine Barrel Stock

Before we get started, I should mention that we're not talking some small operation here. While I don't want to get too specific about company secrets, I will say that the company produces way more than “hundreds” of barrels per day. A lot more. Does that give you a picture? I was stunned by the volume pouring out of this Summerville, South Carolina manufacturing plant.

Without further delay, let's embark on a pictorial tour of how DC Machine produces the barrels you and I see in the market.

barrel stock
DC Machine operation

The raw materials for barrel manufacture show up at the back door as steel bar stock like this. You'll see different lengths of these as it doesn't make sense to cut unnecessary material when making a shorter barrel.

different finish on barrel stock
The raw materials for barrel manufacture show up at the back door as steel bar stock like this.

You'll notice that some raw material stock bars are different colors. This is on purpose. DC Machine has their suppliers coat the raw material with different color finishes to denote the specific type of steel of each bar. It doesn't matter to you as the finish is machined away during the process, but it helps the production line ensure that the right steel is used on the right barrel.

barrel drilling
Step one in the process is to drill out the bore.

Step one in the process is to drill out the bore. There's no rifling at this stage, just a smooth hole of the correct diameter for the final caliber. From this point on, the reference point for machining operations is the bore itself. All exterior material is machined away using the “hole” as a guide.

DC Machine uses a top-secret button rifling process to wring maximum consistency and accuracy out of the barrels. I was able to watch a few being made and was stunned by the smoothness and speed of the operation. Sorry, we can't show it here. Trade secret!

raw barrel truing
Again using the bore as the guide, the barrel blanks are “trued up” by trimming away all excess material that is not perfectly aligned with the bore.

Again using the bore as the guide, the barrel blanks are “trued up” by trimming away all excess material that is not perfectly aligned with the bore. The result is a perfect cylinder with the bore in the absolute center. This helps with machining the final barrel contours later in the process.

barrel making
The result is a perfect cylinder with the bore in the absolute center.

Next up more material is removed and the contours of the final barrel begin to take shape.

DC Machine quality control
During the process from first step on, each machine and step is closely monitored by quality control and the results show up in real-time on plant floor monitors.

During the process from first step on, each machine and step is closely monitored by quality control and the results show up in real-time on plant floor monitors. In fact, Quality Engineer Mark Petty gets notifications on his smartphone the second anything in the process starts to drift away from strict tolerances.

chamber and breech milling
At this stage, the breech end of the barrels are threaded for attachment of the barrel extension and chambers are cut.

At this stage, the breech end of the barrels are threaded for attachment of the barrel extension and chambers are cut.

laser barrel testing
Once barrels start to take shape, they're tested by a laser inspection machine like this one to ensure that all tolerances are far, far better than mil-spec

Once barrels start to take shape, they're tested by a laser inspection machine like this one to ensure that all tolerances are far, far better than mil-spec. Close inspection like this helps the production team know exactly when a certain toolhead in a certain machine needs maintenance or replacement.

barrel manufacturer dc machine
If you look closely at the two barrels on top, you'll see the one on the left has an unfinished muzzle. On the right you can see the crown of the muzzle has been cut.

If you look closely at the two barrels on top, you'll see the one on the left has an unfinished muzzle. On the right you can see the crown of the muzzle has been cut. The idea is to make sure that the internal rifling comes to an abrupt and perfectly clean and smooth end. The tiniest burr or imperfection can harm accuracy as this is the last contact a moving bullet has with the barrel.

barrel extensions
DC Machine also makes barrel extensions. Lots and lots of them.

DC Machine also makes barrel extensions. Lots and lots of them.

Once the barrel extensions are attached, the process is almost complete.

Once the barrel extensions are attached, the process is almost complete.

 

The barrels have been monitored, measured, and lasered for quality control throughout the process. At the very end of the line, just before packaging, is a final visual inspection and hand buffing to remove any rough spots on the exteriors from the machining process.

barrel extension manufacturing
Automated computer-controlled machining equipment.

Part of the reason that DC Machine can produce so many quality barrels per day is the investment in automated computer-controlled machining equipment. Most steps in the process have some way of working on multiple parts of the same type concurrently. Those that don't have automated feed systems, like this, to process parts as quickly as possible.

milling machine upper receivers
This single milling machine is cutting eight upper receivers in one operation.

This single milling machine is cutting eight upper receivers in one operation. By changing out eight parts at once, the operator can produce far more receivers per hour.

upper receiver forgings
upper receiver forgings

DC Machine receives forged aluminum upper receiver blanks. Once in this plant, they're machined to final completion.

cnc machine ar-15 receivers
The more a single machine can do, the fewer changes from machine to machine.

Note now many toolheads are in the conveyor of this single machine. It extends almost to the floor. The more a single machine can do, the fewer changes from machine to machine. That leads to better consistency and higher production throughput.

laser engraving
Ever wondered how that receiver engraving is done?

Ever wondered how that receiver engraving is done? Right here in the laser engraving department. Using the laser is not only fast and precise, it allows for easy changes to the engraving design from batch to batch.

laser engraved lower receivers
Virginia-15 Lower Receiver

DC Machine and Palmetto State Armory often product “meme engravings” on AR lower receivers. This one benefits the Virginia gun rights movement. You might notice the “Lady Freedom” is wearing night-vision goggles, toting an AR-15, and standing on a tyrant.

indoor rifle testing range
Sales Manager and Quality Engineer Mark Petty has this indoor rifle testing range literally in his office.

Sales Manager and Quality Engineer Mark Petty has this indoor rifle testing range literally in his office. If there are questions, or if he simply wants to field test production quality, he can do it right here,

The modern manufacturing process is stunning. This is exactly how the folks at Palmetto State Armory can produce and sell quality rifles at reasonable prices. One of the most fun parts of the tour was seeing Mark's bragging collection. He showed me a couple of custom barrels (I won't mention the names, but they're expensive) that he won betting on the accuracy of a standard DC Machine barrel versus that of one listing at five times the price. That's good stuff for you and me.


About

Tom McHale is the author of the Practical Guides book series that guides new and experienced shooters alike in a fun, approachable, and practical way. His books are available in print and eBook format on Amazon. You can also find him on Facebook, Twitter, Instagram and Pinterest.

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Trapman
Trapman
1 month ago

I own several PSA firearms. I would say they are capable, but not exceptional. But they don’t kill a bank account, either, so there’s that.

musicman44mag
musicman44mag
1 month ago

Ever hear of video?

Steven Mace
Steven Mace
1 month ago

You ran this same story back in January of this year. Must be a slow news day?

Vern
Vern
1 month ago

Maybe I’m gittin where I can’t see as well anymore, mid 70’s, but I didn’t see when they drilled the gas port, before the barrel extension or after the barrel extension?

Ansel Hazen
Ansel Hazen
1 month ago

I have an 11.5″ pistol build and am extremely pleased with the rifle. As others mention, fit and finish were spot on. I think this article shows clearly that PSA deserves more respect for the quality of the product they are putting out.

Ken
Ken
9 months ago

Very proud to know that so many of America’s modern ‘musket’ barrels are manufactured right here in our hometown. We trust PSA and have a quality PSA AR-15.

Boris Badenov
Boris Badenov
9 months ago

I just did a build of a 300BLK using a PSA upper and with a lower kit, the fit and finish was excellent, and OMG the trigger was beautiful, clean crisp, minimal take up and reset. Accuracy was very good, offhand at 38 yards.

Vanns40
Vanns40
9 months ago

I have never, repeat never been disappointed in any PSA product. I purchased a “blemished” upper for my brother at an incredible price. We used a magnifying glass and could not find a single so-called blemish! If there were any they were hiding some place completely out of sight!

JoeUSooner
JoeUSooner
9 months ago
Reply to  Vanns40

I, too, have never been disappointed with any PSA product that I’ve purchased. The quality and reliability have been unbelievable. I’m sold on this company!

Buck
Buck
9 months ago

GOD bless Palmetto State Armory, and ALL other AR manufacturers making affordable and quantity rifles for American Citizens!!!

Green Mtn. Boy
Green Mtn. Boy
9 months ago

No complaints of the accuracy of the PSA products’ couple are what I refer to as exceptional.

Ryben Flynn
Ryben Flynn
9 months ago

I do believe in the early days PSA sourced their barrels from FN-USA (now FN America) which is also in Columbia, SC. HQ in McLean, Va and manufacturing in South Carolina.

Doszap
Doszap
9 months ago

Great article, seems PSA has made the cash to own their own barrel making facility,(except for CHF model barrels.
(FN duplicates), I assume the FN’s CHF’s are now marked as PSA CHF also.