B5 Systems Collapsible Precision Stock Medium for AR-15
Mix and match across the range: 2 items save 5%, 3 save 10%, 4 or more save 15% on your whole basket.
Fits AR-15/M4 rifles with a Mil-Spec-diameter carbine receiver extension (buffer tube). Check your tube specification before ordering.
Not sure it fits your rifle? Ask us before you order
The B5 Systems Collapsible Precision Stock (Medium) is an adjustable precision rifle stock for AR-15 and M4 rifles, fitting any Mil-Spec-diameter carbine receiver extension.
The full-envelope precision stock — the CPS Medium pairs adjustable fit with the reach taller shooters need.
The B5 Systems Collapsible Precision Stock in Medium configuration delivers the CPS system — a precision-adjustable cheek riser and adjustable buttpad on a collapsible Mil-Spec chassis — with a longer extension envelope suited to taller shooters and longer length-of-pull preferences. Eye alignment behind magnified glass becomes a setting you dial in, not a compromise you tolerate.
B5 Systems over-builds its adjustment hardware: the riser and pad lock positively and hold their zeroed positions through recoil, transport and hard positional work. The Medium CPS is the pick for full-size precision gas guns that still need to collapse for the case.
Fits AR-15/M4 rifles running a Mil-Spec-diameter carbine receiver extension (buffer tube). It replaces a standard collapsible stock on the existing tube, so no change of buffer or spring is normally involved. Commercial-diameter tubes are not compatible, so confirm your tube specification first. Set cheek height and pad position at the bench behind your optic; the locks hold your numbers.
| Platform | AR-15 / M4 |
|---|---|
| Fits | Mil-Spec carbine receiver extension |
| Type | Collapsible precision stock |
| Finish | Black, Flat Dark Earth, Coyote Brown, Olive Drab Green |
| Length | Medium |
| Adjustment | Precision cheek riser & buttpad |
| Brand | B5 Systems |
| MPN | CPS-1304 · CPS-1305 · CPS-1306 · CPS-1308 |
Fit, dialled. Order the CPS Medium today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: Rifle & Shotgun Stocks, Precision Rifle Stocks, AR-15 Parts or browse all B5 Systems.
| Platform | AR-15 / M4 |
|---|---|
| Fits | Mil-Spec carbine receiver extension |
| Type | Collapsible precision stock |
| Finish | Black, Flat Dark Earth, Coyote Brown, Olive Drab Green |
| Length | Medium |
| Adjustment | Precision cheek riser & buttpad |
| Brand | B5 Systems |
| MPN | CPS-1304 · CPS-1305 · CPS-1306 · CPS-1308 |
| Category | Rifle Stock |
| Barcode | 814927022201 |
£5 tracked UK delivery on every order via Royal Mail Tracked 24. Our products are ordered in from the manufacturer rather than held in UK stock, so please allow 7 to 10 business days (Monday to Friday, excluding bank holidays) from the date of your order for it to reach you. Tracking details are emailed on dispatch. UK delivery only.
You have 30 days from receiving your order to cancel it for any reason, then 14 days to send it back unused and in its original packaging. Faulty, damaged or incorrect items are replaced or refunded and we cover reasonable return postage. Refunds go back to your original payment method within 14 days of receiving the return.
Any AR-15/M4 with a Mil-Spec-diameter carbine receiver extension. It replaces a standard collapsible stock on the existing tube, so no change of buffer or spring is normally involved. Commercial-diameter tubes are not compatible, so confirm your tube specification first.
The medium body gives a slightly longer reach through its range of positions, which tends to suit shooters using a settled, squared-up position behind a scope or those with longer arms. The <a href="/products/b5-systems-collapsible-precision-stock-short-length">short-length CPS</a> is the one to choose if compact overall length or shooting in kit matters more. If you are between the two, measure your current comfortable length of pull and work from there.
It combines a collapsible carbine body with an adjustable cheek riser and buttpad, so you get repeatable head and shoulder placement without giving up the ability to shorten the rifle for storage or transport. That is the main reason people choose it over a fixed precision stock. It is a B5 design through and through, and the <a href="/blogs/buying-guides/b5-systems-brand-guide">B5 Systems brand guide</a> covers how the range fits together.
The medium CPS is available in Black, Flat Dark Earth, Coyote Brown and Olive Drab Green. Beyond the stock itself you only need your existing buffer tube assembly, though a sling mount is worth thinking about if your current one lives on the old stock. Check what sling attachment you are using before you swap.
Orders leave the United Kingdom with £5 tracked UK delivery in 7–10 business days, and you'll get tracking by email when it ships. If a part turns out to be the wrong fit, see our returns policy or <a href="/pages/contact">contact us</a> and we'll help sort it.
7 to 10 business days from the date of your order. Every order is sent Royal Mail Tracked for a flat £5 and you receive tracking details by email when it is dispatched.
Yes. We list only genuine parts and optics from the brands shown, ordered in from the manufacturer for your order.
Compatibility notes on this page come from the manufacturer. If you are unsure, email us with your make and model before ordering and we will check rather than guess.
Yes. Bundle & Save applies automatically in your basket: 5% off when you buy 2 items, 10% off at 3 items and 15% off at 4 or more. It works across the whole range, so you can mix and match, and there is no code to enter.
Yes — you have 30 days from delivery to cancel for any reason, as long as the item is unused and in its original packaging. See our returns policy for the details.
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