Spike's Tactical Complete M4 Stock Kit for AR Rifles - Includes ST-T2 Buffer, Buffer Tube, Spring, Castle Nut, End Plate - SAK0701-K

Building or upgrading an AR-15? The Spike's Tactical Complete M4 Stock Kit for AR Rifles gives you everything needed to finish your lower receiver with quality, mil-spec components in one package. Rather than sourcing buffer tubes, springs, stocks, and hardware separately, this kit bundles the essential parts—including Spike's ST-T2 Heavy Carbine Buffer—so you can focus on the build instead of the shopping list. Whether you're assembling your first AR or refreshing an existing platform, having matched, trusted parts working together is a real confidence boost.

The kit centers on a 6-position mil-spec buffer tube with an M4 collapsible buttstock, giving you adjustment options for different shooting positions and body armor configurations without sacrificing ergonomics. The ST-T2 buffer is engineered for carbine-length systems and pairs with the included spring to manage recoil and cycling. Finished in black, these components blend function with clean aesthetics on any build.

Spike's Tactical has built a reputation for attention to detail on small parts that matter—your stock assembly is no exception. This is a complete kit, so you're not scrambling for a mismatched castle nut or end plate halfway through; everything comes together as intended. It's the kind of foundational upgrade that separates a cobbled-together build from one that feels cohesive and runs right.

Key Features

• Complete kit—buffer tube, M4 collapsible stock, ST-T2 Heavy Carbine Buffer, spring, castle nut, and end plate included
• 6-position mil-spec buffer tube for length-of-pull adjustment
• ST-T2 buffer optimized for carbine-length AR platforms
• Black finish
• Matched components designed to work together

Specifications

Frequently Asked Questions

What's included in the Spike's Tactical M4 Stock Kit?

The kit includes everything for a complete stock assembly: a 6-position mil-spec buffer tube, M4 collapsible buttstock, receiver end plate, castle nut, buffer spring, and ST-T2 Heavy Carbine Buffer. No additional hardware needed—just install and go.

Will this fit my AR-15?

This kit is designed for AR rifles using mil-spec lower receivers and carbine-length buffer systems. If you have a standard AR-15 or AR platform rifle, this assembly will fit. If your build uses a different system (pistol buffer tube, rifle-length, or proprietary spec), verify compatibility before ordering.

What is the ST-T2 buffer, and why does it matter?

The ST-T2 is a Heavy Carbine Buffer engineered for carbine-length AR platforms. It works with the included spring to manage recoil impulse and ensure reliable cycling. Spike's pairs it specifically with this kit for optimal performance.

How many positions does the buffer tube have?

The included buffer tube is 6-position mil-spec, allowing you to adjust the stock length to suit your shooting setup, comfort, or gear configuration.