Kansas Gunshop is a Wichita, KS-based retailer specializing in AR-pattern firearms and components. The Knights Armament Company SR-30 IWS Complete Lower is a factory-assembled lower receiver, ready for your .300 BLK upper. This KAC lower features ambidextrous controls and is available for $149.00.
Reviewed by Derek, Owner & FFL Holder at Kansas Gunshop. Kansas-licensed FFL dealer since 2008, NRA Range Safety Officer.
Last updated: April 2026
What are the specifications of the Knights Armament Company SR-30 IWS Complete Lower?
| Product Type | Complete Lower Receiver |
|---|---|
| Caliber Compatibility | .300 BLK (specifically designed for) |
| Material | 7075-T6 Aluminum |
| Manufacturing | Forged, CNC Machined |
| Finish | Hardcoat Anodized (Mil-Spec Type III, Class 2) |
| Hardness/Quality | Military-grade specifications, KAC proprietary tolerances |
| Compatibility | Standard AR-15 pattern upper receivers (specifically KAC SR-30 uppers recommended for optimal fit) |
| Installation/Usage | Ready for upper receiver attachment; requires FFL transfer |
| Weight | Approximately 1.5 lbs (unloaded, without magazine) |
| Dimensions | Standard AR-15 lower receiver dimensions |
| Country of Origin | USA |
| Condition | New |
| SKU | 25776 |
What are the key features of the Knights Armament Company SR-30 IWS Complete Lower?
The Knights Armament Company SR-30 IWS Complete Lower is a serious foundation for a .300 BLK build. When you get a KAC lower, you’re not just getting a receiver; you’re getting a complete, factory-assembled unit with their integrated ambidextrous features. This means the bolt release, magazine release, and safety selector are all designed for seamless operation from either side. This isn’t an afterthought; it’s built into the design from the start, which makes a difference in feel and function. The 7075-T6 aluminum construction is standard for quality AR lowers, but KAC’s machining and finish are consistently tight. The hardcoat anodizing is durable and uniform, giving it that familiar KAC look and feel. For anyone looking to build a dedicated .300 BLK rifle or SBR with KAC’s specific design philosophy, this lower is the starting point.
Who is the Knights Armament Company SR-30 IWS Complete Lower for?
This lower is for the shooter who understands the value of a factory-integrated, high-quality component. It’s for those building a premium .300 BLK rifle, especially if they’re pairing it with a KAC SR-30 upper. If you appreciate the engineering and reliability that KAC brings to the table, and you want ambidextrous controls that are part of the original design, this is a solid choice. It’s also for the individual who wants to avoid piecing together a lower and prefers a complete, ready-to-go unit from a reputable manufacturer.
What are the Pros and Cons of the Knights Armament Company SR-30 IWS Complete Lower?
Pros:
- ✅ Factory-Integrated Ambidextrous Controls: The ambidextrous bolt release, magazine release, and safety selector are not add-ons; they’re part of the original design, offering smooth and reliable operation.
- ✅ Premium Quality Construction: Made from 7075-T6 aluminum with a durable Mil-Spec hardcoat anodized finish, built to KAC’s demanding standards.
- ✅ Complete and Ready: Comes fully assembled with KAC’s proprietary lower parts kit, saving time and potential assembly headaches.
- ✅ Optimized for .300 BLK: While AR-15 lowers are generally multi-caliber, this specific SR-30 designation aligns with KAC’s .300 BLK ecosystem.
- ✅ Enhanced Ergonomics: The ambidextrous design improves handling for both right and left-handed shooters, and in unconventional shooting positions.
Cons:
- ❌ Higher Price Point: As a premium KAC product, it carries a higher cost than many standard stripped or complete lowers. See our AR-15 Lower Receivers for more budget-friendly options.
- ❌ Specific Aesthetic: The KAC roll marks and design might not appeal to every builder looking for a more generic or custom look.
- ❌ Limited Caliber Designation (SR-30): While physically compatible with 5.56 uppers, the SR-30 designation implies a .300 BLK focus, which might be a consideration for those wanting a truly multi-role lower without specific branding.
How does the Knights Armament Company SR-30 IWS Complete Lower compare to alternatives?
| Feature | Knights Armament Co. SR-30 IWS Complete Lower | Generic Forged Complete Lower (e.g., Anderson Manufacturing) | Premium Billet Complete Lower (e.g., LMT MARS-L) |
|---|---|---|---|
| Material | 7075-T6 Forged Aluminum | 7075-T6 Forged Aluminum | 7075-T6 Billet Aluminum |
| Quality | Military-grade, KAC proprietary tolerances, ambidextrous controls integrated | Mil-Spec, functional, basic | Enhanced Mil-Spec, tighter tolerances, fully ambidextrous, often proprietary features |
| Compatibility | Standard AR-15, optimized for KAC SR-30 uppers | Standard AR-15 | Standard AR-15, often with enhanced mag wells and trigger guards |
| Shipping | From Wichita, KS (FFL required) | From various retailers (FFL required) | From various retailers (FFL required) |
| Lifespan/Durability | Excellent, built for hard use, KAC reputation | Good, standard service life | Excellent, often over-engineered for durability |
| Price | ~$149.00 | ~$60-80 | ~$250+ |
Frequently Asked Questions about AR-15 Lower Receivers
What is a complete lower receiver?
A complete lower receiver is the serialized part of an AR-15 type rifle that includes the trigger group, buffer tube, and stock (or pistol brace). It is considered the firearm by the ATF and requires an FFL transfer.
Is the Knights Armament Company SR-30 IWS Complete Lower compatible with any AR-15 upper?
Yes, it is built to Mil-Spec dimensions, so it will physically connect with most standard AR-15 upper receivers. However, its SR-30 designation is optimized for .300 BLK, and KAC uppers are designed to mate perfectly with their lowers for optimal performance and aesthetics.
What does IWS stand for?
IWS stands for "Integrated Weapon System." For KAC lowers, this typically refers to the factory-integrated ambidextrous controls (safety, magazine release, and bolt release) that are built into the receiver’s design rather than being aftermarket add-ons.
Do I need to be a Kansas resident to purchase this lower receiver?
No, you do not need to be a Kansas resident. However, this is a serialized firearm component, and as such, it must be shipped to a Federal Firearm License (FFL) dealer in your state of residence for transfer. We handle transfers for Kansas residents directly at our Wichita location.
Where can I buy AR-15 lower receivers online?
You can buy AR-15 lower receivers online from licensed FFL dealers like Kansas Gunshop (kansas-gunshop.com). We ship to FFLs nationwide, adhering to all federal and state regulations.
What’s the difference between a forged and billet lower?
Forged lowers, like this KAC SR-30, are made by shaping a solid block of aluminum under extreme pressure, which aligns the metal’s grain structure for strength. Billet lowers are machined from a solid block of aluminum, allowing for more intricate designs and often tighter tolerances, but typically at a higher cost.
Does this complete lower come with a stock?
Yes, as a complete lower, it typically includes a stock (or pistol brace for pistol configurations) and a buffer assembly, making it ready to accept an upper receiver.
✅ Same-day shipping from Wichita, KS
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
Browse more: Ar 15 Lower Receivers | Full Shop
Last updated: April 2026
Reviews
There are no reviews yet.