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AR-15 Gas Block with Rail – Railed & Clamp-On Options | MSP
AR-15 Gas Block with Rail – Railed, Clamp-On & Front Sight Options
Mount Front Sights & More with a Gas Block That Does It All
A quality AR-15 gas block with rail adds versatility and function to your rifle by giving you a top-mounted Picatinny rail section — perfect for front sights, laser modules, or backup optics. Whether you're replacing a fixed sight block or building a modern custom upper, these railed blocks provide the clearance, precision, and mounting flexibility serious shooters demand.
At Mounts Plus, we carry low-profile, clamp-on, and set screw railed gas blocks for .750” and .936” barrels, from trusted brands like PRI, SADLAK, and EGW — built to mil-spec standards and ready to drop in.
🔥 Benefits of a Railed AR-15 Gas Block
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✅ Add a front sight where none exists
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✅ Mount accessories without a full quad rail
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✅ Ideal for free-float handguard setups
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✅ Available in clamp-on or set-screw options
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✅ Made from steel or aircraft-grade aluminum
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✅ Black Nitride, phosphate, or hardcoat anodized finishes
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✅ Compatible with .750” and .936” barrel journals
Styles We Offer
| Gas Block Type | Description |
|---|---|
| Clamp-On | Easy install without barrel dimpling — perfect for builds or upgrades |
| Set Screw | Classic, secure mount — ideal for long-term setups |
| Railed Gas Blocks | Top Picatinny section allows mounting of BUIS or lasers |
| Flip-Up Sight Blocks | Gas blocks that double as front sights |
💡 Why Use a Gas Block with a Rail?
If your AR-15 features a smooth free-float handguard with no top rail or you want to save weight by deleting a quad rail, a railed gas block offers a clean and stable mounting point for a front sight or small accessories — without adding bulk or requiring permanent modifications.
These blocks allow for co-witnessed iron sights, giving you added reliability and backup aiming capability in case optics fail. They also support front BUIS systems that require exact height alignment with your upper receiver rail.
⚙️ Compatibility
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Barrel journal sizes: .750” and .936”
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Gas systems: Carbine, Mid-Length, Rifle-Length
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Fits most AR-15 upper receivers and barrels
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Designed to match height of standard Picatinny upper rails
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Works with free-float and drop-in handguards
🧠 FAQs: AR-15 Gas Blocks with Rails
Q: What does a railed gas block do?
A: It provides a Picatinny rail on top of your gas block, letting you mount a front sight or accessories without needing a full-length top rail on your handguard.
Q: Can I use a clamp-on gas block with rail?
A: Yes. Clamp-on models are secure and ideal for builders who want to avoid dimpling their barrel. Be sure to torque it properly.
Q: Will this work under a free-float handguard?
A: In most cases, yes. Just make sure your gas block is low profile or has the appropriate dimensions to clear your handguard.
Q: What is the standard rail height for front sights?
A: Many railed gas blocks are slightly lower than receiver height, so check for “same-plane” or “gas block height” sights for proper alignment.
Q: What barrel sizes are available?
A: Most railed gas blocks fit .750” barrels (the most common AR-15 spec), but we also carry blocks for .936” heavy barrels.
🛒 Featured Products
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PRI Railed Gas Block – .750” Steel Clamp-On with Pic Rail
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EGW AR Gas Block with Top Rail – .750”, Set Screw Mount
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SADLAK Railed Gas Block – .936” Steel, Phosphate Finish
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PRI Flip-Up Front Sight Gas Block – Built-in Folding Sight
🔗 Related AR-15 Accessories
🚀 Add Tactical Functionality Without the Bulk
Whether you're upgrading your iron sight setup, building a minimalist upper, or needing an accessory-ready gas block, Mounts Plus has you covered with a curated collection of railed AR-15 gas blocks from the most trusted names in the industry.
🛒 Explore our full lineup above and build smarter with Mounts Plus.