SI Defense Billet
AR Lower Receivers
SI Defense’ AR-style lower receivers are refined and strengthened in key areas to perform flawlessly and to have great aesthetics. Made from 100% billet aluminum guarantees a true dimensions and great looking lower that will be reliable for years of service.
Standard Build Specifications
- Fully machined from solid billet aluminum.
- 5.56/.223 and 7.62/.308 calibers available
- Material: 6061, 7075 or 7050 aluminum.
- Coating: Black anodized to MIL-F-8625F and AMS 2471F.
Do you want your logo or a custom logo on your receivers? We can do it, from military units like The Big Red One or the 25th Infantry to your local police SWAT units, we can customize it!
We can build your standard AR-15 5.56 NATO/.223 or we can build your 7.62 NATO/.308 for some serious knockdown power.
We will be producing forged upper and lower receivers soon because of the large demand. Call or email for more details.
7.62/.308 Lower Receivers
Because the are many different hardware manufacturers and suppliers of the 7.62/.308 receivers, SI Defense produces two different versions of the lowers and two versions of the uppers. These lowers are specifically manufactured to match each respective model. These models are not cross-compatible.
- SI AR-D: Lowers will fit DPMS® magazines and uppers
- SI AR-HK: Lowers will fit HK91/G3® magazines
**SI Defense will build any lower receiver to fit a specific magazine not mentioned above. An additional charge will be assessed for that custom mag-well. Please call for pricing.
We are currently looking for dealers, please let us know if you are interested. You must have your valid FFL license to be considered.