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Sig MCX Stock & Adapters – Folding, Minimalist & Mil-Spec Options | Mounts Plus
Sig MCX Stock – Folding & Minimalist Stock Upgrades for MCX & MPX
Customize Your Sig MCX or MPX with the Perfect Stock
Looking to enhance the performance and ergonomics of your Sig MCX or MPX rifle? Mounts Plus carries a premium selection of Sig MCX stocks and stock adapters that offer improved control, reduced weight, and folding functionality — all engineered to fit MCX and MPX platforms with precision.
Whether you want a folding PCB stock, a minimalist option for weight reduction, or a mil-spec adapter to run your favorite AR-15 stocks, we’ve got your back.
🔧 Shop Our Most Popular MCX Stocks & Kits
✅ MCX/MPX Folding Stock – Magpul SL-K
Rugged and compact, this folding stock combines modern ergonomics with streamlined performance.
✅ Minimalist Plus Folding Stock
Lightweight design with solid cheek weld and quick-deploy folding feature.
✅ MCX Stock Adapter – Picatinny to Mil-Spec
Convert your MCX to accept standard AR-15 stocks with ease.
✅ Folding PCB Kit for MCX/MPX
The ultimate upgrade kit — includes a PCB folding mechanism and Mil-Spec tube compatibility.
🧠 Why Upgrade Your Sig MCX Stock?
The factory MCX stock is functional but can limit customization. Here’s what a stock upgrade delivers:
| Benefit | Stock Upgrade | Factory Stock |
|---|---|---|
| Folding Capability | ✅ Yes | ⚠️ Limited |
| Weight Optimization | ✅ Available | ❌ Heavier |
| Aftermarket Compatibility | ✅ Mil-Spec | ❌ Proprietary |
| Improved Ergonomics | ✅ Enhanced | ⚠️ Basic |
With our range of Sig MCX and MPX stocks, you can tailor your rifle to your mission — whether it’s tactical CQB, hunting, or compact storage.
🔄 MCX vs MPX Compatibility
Most stocks listed here are compatible with both Sig MCX and MPX platforms via the rear Picatinny rail interface. Always confirm your platform's mounting system and whether you need an adapter for Mil-Spec or commercial buffer tube stocks.
🛠️ Types of MCX Stocks We Carry
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Folding Stocks: Ideal for compact storage or transport
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Minimalist Stocks: Lightweight and fast-handling
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Mil-Spec Buffer Tube Adapters: Enables use of AR-15 collapsible stocks
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PCB Folding Kits: Adds side-folding function to fixed tube setups
Need help choosing the right adapter or stock? Contact our support team.
⭐ What Customers Say
“The folding Magpul SL-K with adapter was a perfect upgrade for my MCX. Locks solid, folds smoothly.” – Verified Buyer
“Minimalist Plus Stock is light, fast, and installs in minutes. Highly recommend for anyone building out their MPX.” – TacticalUser300
✅ Why Buy from Mounts Plus?
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📦 Fast shipping on all in-stock MCX & MPX accessories
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🛡️ Trusted parts from leading manufacturers
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🧰 Gunsmith-approved solutions
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🇺🇸 US-based support and service
🔄 Compatible Accessories You Might Like
❓ FAQs About Sig MCX Stocks
Q: Will these stocks work on my Sig MPX?
Yes, most MCX stocks are compatible with the MPX platform if it has a Picatinny rear rail. Always check adapter requirements.
Q: Can I use an AR-15 stock on the MCX?
Yes, with a mil-spec buffer tube adapter, you can use most AR-15 stocks.
Q: What’s the lightest stock for the MCX?
The Minimalist Plus stock is designed for ultralight builds without compromising durability.
🛒 Upgrade Your Sig MCX Today
Don’t settle for standard. Choose a stock upgrade that improves control, reduces weight, and folds when you need it.