The highly compact Magpul MOE SL-K is smallest and lightest of the company’s AR-pattern butt stocks.

Its high speed, low drag nature is perhaps best appreciated in comparison with some of Magpul’s better known products – including the iconic CTR.

Top to bottom: ACS, CTR, SL-K


Indeed, I’ll be using the CTR to benchmark against the SL-K, where necessary, throughout the article.

I can still remember when the CTR was a modern stock and while it’s as good as it ever was – and still very much issued/massively popular – things keep moving; you only have to look at the design and uptake of BCM stocks and Magpul’s very own MOE SL (the K’s big brother) to consider that.

Reference pic from @btl_ltw showing BCM stock
Reference pic from @btl_ltw showing MOE SL

And yet…the OG CAR stock also remains popular. We’ll come back to that later.

I’d spotted the SL-K in an increasing number of reference pics, along with its deluxe sibling – the MOE SL – and the BCM as mentioned earlier. On a whim, I decided to give the SL-K a go – and I’m very glad that I did.

Reference pic
Reference pic

I ordered it in FDE, from Brownells UK.


Cheek Weld

Compared with the CTR, the cheek weld of the SL-K is subtly improved – in line with Magpul’s modern generation of stocks. It’s not a huge shelf like the ACS, but there’s enough there to change the feel for the better. It’s just the right balance, aiming squarely between overt and minimal.


Considerably shorter than the CTR, the SL-K’s rubber butt pad is differently textured, and differently angled. Avoid right now if you prefer a lot of shoulder contact. However, for those who prefer the unobtrusive quality of the CAR stock (and many do), the SL-K could be a good shout. However, while minimalist like the CAR, its mode of shoulder contact is totally modernised.

At the base of the butt pad there’s a toe which has been missing from previous Magpul designs. This allows the stock to be more easily rolled up in to firing position from low ready. It also makes for a better fit with body armour. That said, like all new accessories which change the rifle’s ergonomics, it took some getting used to.

One other thing I noticed with use, which is really worth pointing out, is that the SL-K is really convenient when switching shoulders and transitioning to my support side (left handed shooting). The stock’s form factor makes the entire process less cumbersome and more natural – I no longer have to ‘jump’ the butt to clear my sling, because the butt is so short.

Sling Compatibility

A 1.25″ slot (footman’s loop) exists where a sling can be threaded.

It’s also compatible with Magpul’s M-LOK QD Sling Mount, where the user wishes to run a QD sling loop. This is an additional extra.

In addition to these features, a cut out at the lower leading edge of the stock ensures clearance for receiver end sling mounts like the Magpul ASAP, with stock retracted.

Anti-Snag Dual Side Release Lever

There’s no separate locking mechanism with the SL-K – as opposed to the CTR. The only adjustment control is provided by the obvious lever. A bifurcated structure, it is available to the user on both sides of the stock and is protected from snagging and accidental release by a hefty bulwark – the SL-K’s lower edge.

With the lever depressed fully, a useful portion of the locking mechanism is exposed. By inserting an appropriate fulcrum into the hole that’s revealed, the stock’s lock pin can be pulled fully proud of the receiver extension end stop. Thus, the stock is easily removed from the receiver extension. It’s a hell of a lot easier than the CTR.

Is There Any Wobble?

Lack of a separate CTR-like locking mechanism may make some users shudder. Doesn’t the stock rattle? That will depend partly on how well the user’s receiver extension fits the stock’s inner diameter. With my Colt Canada receiver extension the fit is excellent, and Magpul appears to have tightened the stock’s tolerances in this area when compared with the rather baggy CTR (which relies wholly on its friction lock). They’ve also done something a bit different inside.

As well as the usual sprung steel pin which locks into the stock position holes in the receiver extension, Magpul has extended the adjustment lever into the stock as an anti-rattle measure. So, when pressure is released from the lever and the steel pin springs into place, so too does the anti-rattle structure.

It’s not a hardened concrete-like lock up, but in my implementation any wiggle is so minimal as to be unobtrusive.

Weight and Dimensions


Utilising uncomplicated construction and requiring fewer materials, on paper it’s easy to see why the SL-K costs significantly less than the CTR. That said, don’t be fooled into thinking it’s any less well designed than it’s forebears (like the CTR) or siblings (like the SL).

In addition, the SL-K uses the very same plastic as the CTR – Magpul’s plastics still arguably the best in the firearms industry. It’s tough, exhibits a pleasing texture and it feels like quality.

However, while the lack of an integrated QD sling swivel socket makes it cheaper, if you require the relevant M-LOK accessory the price goes up. So that’s worth thinking about before you buy.

For further information, Magpul has a really good series on its stocks and the video I’ve linked here and below is a great overview of the compact/non-storage types it produces – of which the MOE SL-K is a part:

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