Magpul Stock CTR Collapsible AR-15 Mil Spec Black – MAG310-BLK

The Magpul Stock CTR Collapsible AR-15 mil spec stock in black is the answer for shooters who want an adjustable stock that does not rattle. It fits standard mil spec buffer tubes, collapses through the usual range of positions, and adds a friction lock that removes the play most collapsible stocks live with. That single feature is why it has been a default upgrade for years.

Stocks are where a rifle meets your shoulder and your cheek, and slop there costs you consistency on every shot.

What the Magpul Stock CTR Collapsible Design Delivers

This is a lightweight, adjustable buttstock built for AR-15 pattern rifles running mil spec diameter receiver extensions. Adjustability matters more than most people credit, since length of pull needs to change with body armor, heavy winter clothing, or simply a different shooter using the rifle.

The Magpul Stock CTR Collapsible unit adds a supplemental friction lock on top of the standard adjustment lever. Engaging it clamps the stock against the buffer tube and eliminates the wobble that makes a cheap collapsible stock feel loose against your cheek, which is the difference between a stock you tolerate and one you trust.

Key Features

• Fits standard mil spec AR-15 receiver extensions
• Supplemental friction lock that removes stock-to-tube play
• Multiple length of pull positions for different shooters and gear loads
• Reinforced polymer construction that keeps weight low
• Sloped cheek weld surface for a repeatable head position
• Black finish that matches standard AR furniture and receivers

Construction, Lockup, and Ergonomics in Detail

Reinforced polymer is the right material here. A buttstock takes impact from being set down, dragged across gear, and occasionally used to brace against a barricade, and a good polymer absorbs those hits without cracking while staying substantially lighter than any metal alternative.

The friction lock is the headline. Collapsible stocks must have clearance to slide, and that clearance becomes wobble the moment you press your cheek into the stock. Clamping the stock down converts an adjustable stock into a rigid one for as long as you want it, and releasing it restores full adjustment in a second.

The cheek weld surface is shaped rather than flat, which encourages the same head position shot after shot. Consistent cheek placement is what makes a red dot or a scope repeatable, because a head that shifts changes the sight picture even when the rifle has not moved at all.

Practical Use, Installation, and Care

Installation is fast. Depress the adjustment lever fully, slide the old stock off the buffer tube, and slide the new one on the same way. Confirm the stock indexes on the tube positions correctly and that the lever releases cleanly at each stop before you take the rifle out.

Set your length of pull with the gear you actually wear. Measure with the plate carrier or the winter jacket on, not in a t-shirt on a warm afternoon, because the position that feels perfect in the living room is often one notch too long in the field.

Maintenance is minimal but not zero. Wipe grit off the buffer tube where the stock rides, since sand and dust in that channel cause the stock to bind and wear the tube finish. Check the friction lock periodically so it still clamps firmly against the tube.

Verify the stock is mil spec compatible with your build before ordering. Commercial diameter buffer tubes are slightly larger than mil spec tubes, and a mil spec stock will not slide onto a commercial tube.

Pair the Magpul Stock CTR Collapsible stock with a matching grip and handguard for a coherent build, and browse our parts and upgrades collection for the supporting parts.

A stock that locks up solid makes a rifle feel like a single piece rather than an assembly. That confidence is worth far more than what this part costs. Ships direct to your door, no FFL required.