Magpul Industries

Magpul ACS-L Carbine Stock Mil-Spec for AR-15/M4

Name: Magpul ACS-L Carbine Stock Mil-Spec for AR-15/M4
Brand: Magpul Industries
SKU: MAG378-BLK

£105.00

VAT included.

£5 Tracked Delivery · 7–10 Business Days

Estimated delivery: Tue 8 Sep – Fri 11 Sep

Stock is imported from the USA to us, then shipped to you from the UK — we cover all duties and import charges, so there is nothing to pay on delivery.

Colour: Black

Bundle & Save

Any 2 items

Save 5%

5% off your whole order

2 of this item

~~£210.00~~ £199.50

£99.75 each

Product Overview

The Magpul ACS-L is a mil-spec carbine stock with onboard battery storage for AR-15 and M4 rifles, fitting any Mil-Spec-diameter receiver extension.

ACS capability on a diet — the ACS-L keeps the locked-down weld and battery storage while shedding the bulk.

The Magpul ACS-L Carbine Stock (MAG378) — Adaptable Carbine/Storage, Light — streamlines the full ACS concept for shooters who want its wobble-resistant stability and onboard battery storage without the width and weight of the flagship. The friction-lock interface still clamps the stock firm against the receiver extension for a stable, repeatable cheek weld; the storage slims down to efficient battery tubes rather than full compartments.

The slimmer housing handles faster and clears kit more cleanly, while the rubber buttpad and reinforced polymer construction carry the usual Magpul guarantees. It is the pragmatic middle path of the stock line — most of the capability, noticeably less of the mass.

Why shooters choose the ACS-L

Friction-lock stability — a firm, wobble-resistant weld
Streamlined battery storage — essentials onboard, bulk offboard
Slimmer, lighter housing — faster handling than the full ACS
Rubber buttpad — positive shoulder contact
Three finishes — Black, Flat Dark Earth, Olive Drab Green

What the ACS-L fits

Fits AR-15/M4 rifles with a Mil-Spec-diameter carbine receiver extension (buffer tube). Commercial-diameter tubes are slightly larger and will not take it, so check your tube specification before ordering — if you are not sure which you have, measure the tube or contact us with your rifle's make and model. Slide on, set length, engage the lock; battery tubes load from the rear.

Specifications

Platform	AR-15 / M4
Fits	Mil-Spec carbine receiver extension
Type	Collapsible carbine stock with battery storage tubes
Material	Reinforced polymer
Finish	Black, Flat Dark Earth, Olive Drab Green
Adjustment	Friction lock
Brand	Magpul Industries
MPN	MAG378-BLK · MAG378-FDE · MAG378-ODG

The lighter way to lock down. Order the ACS-L today — in stock at Xtreme Tactical Gun Parts with £5 tracked UK delivery in 7–10 business days.

Explore more: Rifle & Shotgun Stocks, Precision Rifle Stocks, AR-15 Parts or browse all Magpul.

Compatibility & Fitment

Fits AR-15/M4 rifles with a Mil-Spec-diameter carbine receiver extension (buffer tube). Check your tube specification before ordering.

Please confirm platform, interface and fitment requirements before ordering.

Technical Specifications

Platform	AR-15 / M4
Fits	Mil-Spec carbine receiver extension
Type	Collapsible carbine stock with battery storage tubes
Material	Reinforced polymer
Finish	Black, Flat Dark Earth, Olive Drab Green
Adjustment	Friction lock
Brand	Magpul Industries
MPN	MAG378-BLK · MAG378-FDE · MAG378-ODG
SKU / MPN	MAG378-BLK
UPC / Barcode	873750006314

Shop Related Categories

Shop AR-15 Parts & Accessories View category

Shop Magpul AR-15 Stocks View category

Shop Magpul Industries View category

Shop Rifle & Shotgun Stocks View category

Related Buying Guides

Not sure which option is right for your build? These guides break it down.

Buying Guide How to Choose an AR-15 Stock: Fit, Length of Pull & Platform

Buying Guide Best AR-15 Upgrades Under £100 (That Actually Make a Difference)

View all buying guides →

Product Questions

Will the ACS-L fit my buffer tube?

It is made for AR-15/M4 rifles with a Mil-Spec-diameter carbine receiver extension. Commercial-diameter tubes are slightly larger and will not take it, so check your tube specification before ordering. If you are not sure which you have, measure the tube or contact us with your rifle's make and model.

What does the L in ACS-L mean in practice?

The ACS-L is the slimmer, lighter version of the ACS: it keeps battery storage but uses streamlined tubes rather than the fuller compartments of the standard stock. That gives a less bulky stock that still carries a few essentials. If storage volume matters more than profile, look at the standard ACS (MAG370).

What is the storage like?

It has battery storage tubes built into the body, sized for small items rather than bulky spares. They are closed off within the stock so contents are not rattling loose on the rifle. Check what you intend to carry will physically fit before relying on it.

Which finish, and what do I need to fit it?

Black, Flat Dark Earth and Olive Drab Green are available, all identical apart from colour. Swapping a carbine stock is usually just a matter of releasing the adjustment lever and sliding the old stock off the tube, so no special tooling is normally involved. If you are still choosing, our AR-15 stock guide compares the options.

How is a stock delivered, and can I return it?

Stocks are dispatched from the United Kingdom with £5 tracked UK delivery in 7–10 business days and tracking is emailed once the parcel is on its way. If the buffer tube diameter turns out to be wrong, see our returns policy or contact us and we'll help sort it.