The BCM Milspec Carbine Stock Hardware Mounting Kit is a complete receiver extension assembly for AR-15 and M4 rifles — buffer tube, receiver end plate, castle nut, carbine action spring and carbine buffer — and it does not include a stock.
There is no stock in this box. This is the hardware that mounts a Mil-Spec stock you already own.
Bravo Company USA's name for this kit mentions a stock, and some retailers list the same part more plainly as a buffer tube assembly, which is what it actually is. You get the Mil-Spec 6-position receiver extension machined from 7075-T6 aluminium, the receiver end plate, the M4 castle nut, the carbine action spring and the carbine buffer assembly. Bolt those to a lower receiver and you have everything a Mil-Spec stock needs to slide onto — except the stock.
That makes it the right purchase when you already have a serviceable stock and want fresh, correctly specified hardware behind it, or when you are building a lower from parts and want the tube assembly from one manufacturer. If you want the stock as well, the Gunfighter Stock Kit Mod 0 in Black is this same hardware supplied with the Mod 0 stock fitted. Ordering this kit expecting a stock is the single most common mistake on this part, so it is worth a second look before you check out.
Why shooters choose the Milspec Carbine Stock Hardware Mounting Kit
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Hardware only, priced accordingly — you are not paying twice for a stock you already own
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7075-T6 receiver extension — 6-position, machined to Mil-Spec dimensions
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Complete assembly — tube, end plate, castle nut, action spring and buffer in one box
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Matched components — spring and buffer specified together rather than mixed from a parts bin
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Broad stock compatibility — takes Mil-Spec stocks from a range of makers
What the Milspec Carbine Stock Hardware Mounting Kit fits
Fits AR-15/M4-pattern lower receivers with a standard threaded rear, including UK straight-pull AR-15 builds, where the buffer and action spring return the carrier after each hand-cycled stroke. Bravo Company USA lists the kit as compatible with Mil-Spec dimension stocks from BCM, VLTOR, LMT, Magpul CTR-M, Stag Arms and Colt. Because the receiver extension is Mil-Spec diameter, a commercial-diameter stock will not fit it. Remember that no stock is supplied: you must already have one, or buy one separately. Fitting needs a castle-nut wrench, and the castle nut should be torqued and staked or thread-locked.
Specifications
| Platform |
AR-15 / M4 |
| Fits |
AR-15/M4 lower receivers with a standard threaded rear; Mil-Spec dimension stocks |
| Type |
Stock mounting hardware — receiver extension, receiver end plate, castle nut, carbine action spring, carbine buffer. No stock included |
| Material |
7075-T6 aluminium receiver extension |
| Adjustment |
6-position receiver extension |
| Brand |
Bravo Company USA |
| MPN |
BCM-STOCK-HARDWARE-KIT |
The hardware, correctly specified, with no stock you did not ask for. Order the Milspec Carbine Stock Hardware Mounting Kit today — in stock at Xtreme Tactical Gun Parts with free tracked UK delivery in 7–10 days.
Explore more: AR-15 Parts & Accessories, Rifle & Shotgun Stocks or browse all Bravo Company USA.