Down and Dirty with the San Tan Tactical STT-15 Pillar Billet Receiver Set

STT-15 Review By: Nomad

 Photography By: Nomad & Will


“STT-15 PILLAR Billet Receiver Combo by San Tan Tactical – Your Final Answer! 

The most advanced yet simple AR lower receiver ever made!”


STT-15 Review:

I was super excited to hear from Will at Black Sheep Warrior when he asked me to build out and field test a receiver set from Chandler Ariz. based, San Tan Tactical (STT).  Possibly like some of you, I had never heard of STT. 

First order of business, visit google and recon this company. I quickly located their website ( and began studying their handiwork. I could tell by their mission statement they seemed to care a lot about their work and their customers. The photos and videos on their website were well done and the site itself was very easy to navigate. After I had scoured the entire site, I got offline and began thinking about what parts I would choose to mate with the inbound receiver set.

When the San Tan Tactical receiver set arrived, I studied every inch of the billet machined aerospace grade American aluminum. 

The set I received was coated with black MIL-A-8625 hard anodizing as I was going for the more traditional look. For customers wanting something other than black, San Tan Tactical offers their receivers in Flat Dark Earth, Tungsten Grey, Coyote Brown, Burnt Bronze, Prism Pink, or OD Green Cerakote for an additional $39; a great way to add customization to any rifle.  

As I held the lower receiver, I was amazed at how light it was. The San Tan Tactical logo (complete with menacing desert iguana, a nod to their southwest location no doubt) and American Flag had been engraved on the right side offering a level of custom distinction unavailable on many “other brand” receivers. The oversize trigger guard with shooter ready finger rest was a nice touch, but what really caught my eye was the generous magazine well flare. 

The quality workmanship is evident in every aspect of the receivers, including the custom cut and matching controls that are included.

I quickly began fishing through my gear for a test magazine. A MAGPUL PMAG found my hand first and slid right into the receiver without hesitation. Other points to note include; full ambidextrous quick attach points, bolt release, and magazine release, all pre-installed. The oversized texturing on each of the controls would no doubt assist in locating them when the time comes, and the heartburn necessary for installing each little control had fallen to someone else. So far, so good…. 

The upper receiver was just as sleek to look at. It had several pre-installed components, including the ejection port cover and forward assist. The top featured machined in T-markings for easy optic relocation and the left side included STT “Truss Pockets” for increased structural rigidity and yet another touch of customization.

Together, the matched upper and lower receivers  are truly works of art. Dropping in a takedown and pivot pin allowed me to see how well this pair had been matched. Now I just needed some time to turn these two pieces of aluminum into a rifle that could throw some lead down range.

When it was time to start building out the receivers, I decided to go with some no frills Mil-spec components. I figured the best way to isolate the San Tan Tactical receiver’s true performance was to match it up with some everyday pins, springs, etc… and see what would happen. Since most of the set was already assembled at San Tan Tactical, all that was needed would be a trigger, safety selector, buffer tube assembly, pistol grip and some take down pins for the lower. We decided to drop in a Battle Arms Development Ambidextrous Safety Selector to complete the ambidextrous nature of this build. The lower will accommodate either a 90 degree or a 45 degree selector. Battle Arms Development makes both; we opted for the traditional 90.

As I held the lower receiver, I was amazed at how light it was.

For the upper, all we needed was a bolt carrier group and charging handle. We went with a Fathom Arms BCG (read the Will’s review) and Strike Industries charging handle.  

We only hit three snags during assembly. The first was when we dropped in the safety selector spring and found we had too much spring to be functional or even operational. A quick snip with the cutters turned the spring into custom length and the problem was solved. A second snag was when we installed the buffer spring retention pin. It was a bit tight, so we made the hole slightly bigger using a drill bit and we were back in business. Once we had the receivers assembled, we began fitting the barrel, (Aero precision 16″) gas block, gas tube and Parallax FFSSR M-LOK rail system into place to complete the rifle.

The barrel was noticeably tight at first glance, and before I got the hammer out to make it work, I called San Tan Tactical. Even on a Saturday, the customer service department answered right up and was not surprised to hear of how tight the barrel fit was on the upper. STT said that a combination of tight specs and possibly a little too thick of anodizing (San Tan Tactical mentioned that they had since discovered a batch of slightly over anodized receivers) was the culprit.

The truly ambidextrousness of the platform makes deployment and execution of the system unbelievably simple.

They suggested throwing the barrel in the freezer and heating the upper with a hair dryer to complete the assembly. I was a little hesitant to try this tactic, but since STT was claiming it might be necessary – I went ahead and it worked.

In the end, we had everything fitting together and ready for the range.  

Range day came and I headed out to see how this machine would stand up. Right out the gate everything performed flawlessly. Cycle rates were good, controls all worked as they should, and before long we were dumping round after round downrange. No jams or double feeds to speak of.   

To test the functionality of the ambidextrous controls, I performed a series of shots followed by magazine reloads. First, as a right handed shooter, with the controls I have been trained to use. Second as a south paw shooter would do when utilizing this San Tan Tactical platform. As we suspected, each control had been placed perfectly and designed in a way that could be found with bare hands or while wearing gloves. 

Throughout the review process I was in contact with Dennis Harless, owner of San Tan Tactical. He was very easy to talk to and always able to answer my questions. “One thing STT has been fighting against since the beginning,” he told me, “is the idea that STT receivers are only for lefty shooters.” That’s funny I thought, because in reality any right or left handed shooter can quickly find themselves needing to transition to their non-dominant hand when circumstances dictate. I do see value in left handed shooters having access to all the normal controls, us, right handed shooters have. However, I see more value in every shooter having a truly ambidextrous platform that can be operated with precision from either shooting hand. That is exactly what STT has created here, and that is why I am so interested in their product. A truly ambidextrous platform, that feels and operates flawlessly and reliably, in either of your shooting hands.  

In closing, San Tan Tactical has clearly made a top shelf receiver set. The receivers are premium priced, and when you consider what you are actually getting – it’s well worth the money.

The quality workmanship is evident in every aspect of the receivers, including the custom cut and matching controls that are included.

So the question you should be asking yourself right now is – which one am I going to order?

The truly ambidextrousness of the platform makes deployment and execution of the system unbelievably simple. This translates to more shots on target and less time fumbling through magazine exchanges, etc… – especially when things get hairy and you have to transition to your non-dominant shooting hand. The customer service at STT proved to be helpful and knowledgeable throughout my review process. Dennis stands behind his products and offers a lifetime guarantee on each receiver he creates, yet another guarantee you won’t find with a lot of “other” companies. Pair that with being made in the good ole U.S.A. and it makes it pretty hard to beat. So the question you should be asking yourself right now is – which one am I going to order?


Currently, San Tan Tactical ( has several options for getting your hands on their receivers. They are offering their receiver combo sets (as reviewed) for a special introductory price. Additionally they offer a variety of safety selectors, take down pin sets, triggers, stocks, engraving and Cerakote options for additional cost. 

If you are looking for a standalone upper or lower, both are available. 

A fourth option is their “grenade” (blem) lowers. San Tan Tactical states they are mechanically perfect but will have a few minor cosmetic issues. Currently they are available, for a special introductory price.  



MAGPUL Back Up Sights

Parallax Tactical Lightweight FFSSR MLOK Rail

Troy Industries Claymore Muzzle Break

Battle Arms Development Ambidextrous Safety Selector

Fathom Arms Bolt Carrier Group 

Aero Precision 16″ Chrome lined barrel

About the Author:

“Nomad” is a law enforcement professional. He has a background in photography and I am lucky to call him a friend and fellow brother in arms. Thanks for taking the time to write this review and for putting up with me bro!

– Will




Do you have a San Tan Tactical build? Want one? Leave a comment below and share a picture of your build or feel free to ask a question!