What types of stocks can I use with the Sig MCX stock adapter?

You can use AR-style buffer tube stocks or 1913 rail-compatible folding stocks depending on the adapter model selected.

Is this stock adapter compatible with the Sig MCX Virtus?

Yes. All adapters listed are fully compatible with the Sig MCX Virtus, as well as other MCX Gen 1 and Gen 2 variants like the SBR and Patrol.

Does installation require any modification to the firearm?

No. These adapters are designed for drop-in use and mount directly to the factory rear receiver interface using standard tools.

Can I use this adapter to install a pistol brace?

Yes. Most pistol braces that use buffer tubes or 1913 rail mounts are compatible with these stock adapters.

Sig MCX Stock Adapter – AR Buffer Tube & 1913 Folding Mounts | Mounts Plus

**KNS Compact AR/MCX Stock Adapter** $72.29

**KNS AR/MCX Stock Adapter WITH Flange** $72.29

**KNS AR/MCX Stock Adapter Without Flange** $72.29

Sig MCX Stock Adapter – 1913 & AR-15 Compatible Solutions

Upgrade your Sig MCX with a high-quality stock adapter designed to enhance modularity and allow compatibility with a wide range of folding stocks, braces, and AR-style buffer tubes. Whether you're building a compact SBR, converting to an AR-15 stock setup, or just looking for more flexibility, Mounts Plus offers Sig MCX stock adapters that fit securely and install easily.

All adapters are engineered for reliability, compatibility with Gen 1 & Gen 2 MCX platforms, and are ready to support your build — no gunsmithing required.

🛒 Top Sig MCX Stock Adapter Options

Product	Style	Compatible Platforms	Price
KNS AR/MCX Stock Adapter with Flange	AR-15 Buffer Tube	MCX Virtus, Patrol	$72.00
KNS AR/MCX Stock Adapter without Flange	AR-15 Buffer Tube	MCX Virtus, Patrol	$72.00
MCX 1913 Folding Stock Adapter Kit	1913 Rail / Folder	MCX & MPX	$160.29

✅ All adapters include necessary mounting hardware and are drop-in ready for standard MCX receivers.

✅ Why Use a Sig MCX Stock Adapter?

🔩 Install AR-Style Stocks – Easily mount your preferred buffer tube stocks like the SBA3, Magpul SL-K, or MFT Battlelink
🔄 Enable Folding Stock Configuration – Pair with 1913-compatible hinges for compact transport and storage
⚙️ Modular Flexibility – Run your MCX as a PCC, SBR, or full-length carbine with your ideal setup
🧰 No Gunsmithing Required – Installs using existing receiver interface and basic tools
🛡️ Built for Duty & Defense – Trusted by tactical shooters and law enforcement

📐 Which Adapter Do You Need?

🔹 KNS AR/MCX Adapter – With Flange

Designed to accept AR-15 buffer tubes. The flange adds extra stability for folding stocks or heavier setups.

🔹 KNS AR/MCX Adapter – Without Flange

Slimmer fit for minimalist builds. Still supports buffer tube mounting but with a lower-profile appearance.

🔹 1913 Folding Adapter Kit

Mounts to MCX rear rail and accepts 1913-based folding stocks or braces. Perfect for compact SBR or truck gun builds.

🔧 Installation Notes

All adapters fit MCX Gen 1 and Gen 2 receivers
Uses factory rear receiver threads
No modifications to the lower or upper required
Compatible with most folding stock hinges and pistol brace mounts

🛠️ Need install tools? Shop Gunsmith Tools →

📚 Frequently Asked Questions (FAQ)

Q: What stocks work with the Sig MCX stock adapter?
A: AR-style stocks (buffer tube-mounted) or 1913-compatible folding stocks will work depending on the adapter model.

Q: Is this adapter compatible with the MCX Virtus?
A: Yes. All adapters listed are tested and verified for compatibility with MCX Virtus, Patrol, and SBR models.

Q: Do I need to modify my MCX to install this?
A: No. These are drop-in adapters that mount directly to the factory rear interface without permanent modification.

Q: Can I use this to mount a pistol brace?
A: Yes. Most braces that use a buffer tube or 1913 hinge (like the SB Tactical FS1913) are compatible.