The STT-15 is 100% compatible with any Mil-Spec lower parts kit. You will have a few extra parts as STT includes the ambidextrous bolt catch assembly and the ambidextrous magazine catch assembly with your new lower receiver.

Our lowers are CNC machined directly from a single block of 7075 T-651 Aerospace grade aluminum.

We machine them directly from a billet of A-2 Tool Steel. 

Yes it will! We designed the lower to give you the widest and deepest possible magazine well flair while maintaining full magazine compatibility.

Absolutely. The STT-15 will accept ALL Mil-Spec AR-15, M4, M-16 components. Excluding the included ambidextrous controls. 

Our warranty is simple. We will do whatever it takes to make sure our customers are completely happy with their new purchase. If for any reason something isn’t meeting your expectations please contact us immediately so we can get it taken care of right away!

If you have a Mil-Spec LPK you already have more than enough. If not and you would like to get each of the parts you will need separately, here is a list.

• Front & rear takedown pins with springs and detents.

• Safety selector with spring and detent.

• Fire Control Group with pins.

• Buffer assembly including castle nut, end plate, buffer tube, action spring, and buffer.

Your new STT-15 will come fully assembled with any additional parts that you have chosen! (Excluding the Trigger add on)

We do! STT makes the lower and all of the controls in house right here in Fort Worth, TX.

Yes. Per the Bureau of Alcohol, Tobacco, Firearms, & Explosives we must ship all firearms to an FFL in your state of residency.

The best way to get us your dealer’s license is to put their contact information into your order when prompted at checkout. Then have your dealer E-mail us a copy of their license to FFL@SanTanTactical.com or if your dealer prefers to fax it to us they can send it to 480-393-4018.

Generally, there is 1 week lead time for Cerakoting if we don’t have it coated already. We keep a lot of different colors in stock and ready to ship. However it would be impossible to keep the different selector styles, and with logo and without the logo of STT-15’s in every color, in stock at all times.

Some would say we have a biased opinion however just compare the features the STT-15 includes. If you would like please feel free to contact us to talk about it and we can answer any questions you may have.

We do! Please contact us and let us know which rifle you are looking for specs on and we can send the build out list out to you.