Blemished PSA AR-45 Billet Rifle Lower Build Kit, M4 Style Carbine Buttstock

Blem PSA AR-45 .45 ACP Billet Rifle Lower Build Kit, M4 Style Carbine Buttstock

This is a Blem PSA AR-45 rifle lower build kit chambered in .45 ACP, built around a PSA PX45 billet 7075-T6 aluminum lower receiver with a hardcoat anodized finish and Glock-style .45 ACP magazine compatibility. The receiver comes with a proprietary magazine catch and proprietary ejector already in place, along with a non-last-round bolt hold open specific to this platform. The lower parts kit, Mil-Spec heavy-duty 6-position carbine buffer tube, 8 oz heavy buffer, standard AR-15 carbine recoil spring made in the USA, AR-15 M16 Mil-Spec receiver end plate, and AR-15 carbine castle nut round out the included component set. A Davidson Defense AR-15 and M16 Mil-Spec 6-position M4 style carbine buttstock in 6061-T6 aluminum with an integrated sling loop closes out the rear end. This kit is purpose-built for the AR-45 platform and requires customer-supplied parts and hands-on tuning to get running reliably. It is not a beginner build. The Blem designation means the receiver will have cosmetic imperfections that do not affect function.

Key Features

• .45 ACP chambering, AR-45 platform
• Blem PSA PX45 billet 7075-T6 aluminum lower receiver, hardcoat anodized
• Glock-style .45 ACP magazine compatible
• Proprietary magazine catch included
• Proprietary ejector included
• Non-last-round bolt hold open
• Complete Mil-Spec AR-15 lower parts kit
• Mil-Spec heavy-duty AR-15 6-position carbine buffer tube
• 8 oz heavy buffer, color and style may vary
• Standard AR-15 carbine recoil spring, made in the USA
• AR-15 M16 Mil-Spec receiver end plate
• AR-15 carbine castle nut
• Davidson Defense AR-15 and M16 Mil-Spec 6-position M4 style carbine buttstock, 6061-T6 aluminum, black, integrated sling loop, Mil-Spec buffer tube compatible
• Blem receiver, cosmetic imperfections do not affect function

Perfect For

• Experienced AR-45 rifle builders sourcing a .45 ACP lower build kit with a Mil-Spec M4 style stock included at a reduced price point
• Builders who understand the AR-45 platform and are prepared to tune and source additional parts for reliable function
• Shooters who want a PSA PX45 billet receiver as the foundation of an AR-45 rifle build and are comfortable working through platform-specific fitment requirements

PSA PX45 Blem Billet Lower Receiver

The PSA PX45 billet lower receiver is machined from 7075-T6 aluminum with a hardcoat anodized finish and is purpose-built for the AR-45 platform. It accepts Glock-style .45 ACP magazines through a proprietary magazine catch that is already in place on the receiver. The proprietary ejector is also installed and is specific to the .45 ACP AR platform. The bolt hold open on this receiver is non-last-round, a platform characteristic of the AR-45 design. This is a Blem receiver, meaning it will have cosmetic imperfections that may include forging marks under the finish, minor scratches, slight variations in finish color, or coating inconsistencies. None of these affect the structural integrity or function of the receiver.

Lower Parts Kit and Buffer System

The complete Mil-Spec AR-15 lower parts kit covers the internal lower component group, including the fire control group, magazine catch hardware, bolt catch, and all associated pins and springs. The Mil-Spec heavy-duty 6-position carbine buffer tube, 8 oz heavy buffer, and standard AR-15 carbine recoil spring made in the USA form the buffer system at the rear of the lower. The AR-15 M16 Mil-Spec receiver end plate and AR-15 carbine castle nut lock the buffer tube down at the rear of the lower receiver. The Davidson Defense M4 style carbine buttstock in 6061-T6 aluminum fits directly onto the Mil-Spec carbine buffer tube and closes out the rear end of the build with a 6-position adjustable length of pull and an integrated sling loop for sling attachment. The all-aluminum construction of the stock keeps the rear end solid and consistent with the Mil-Spec buffer tube profile. Buffer color and style may vary.

Builder Requirements

This kit is not for beginners and is not a drop-in build. The AR-45 platform requires customer-supplied parts and significant hands-on tuning to get running reliably. Builders unfamiliar with AR-45 platform-specific fitment, timing, and component requirements should not purchase this kit. If you are not experienced building AR-45s and are not prepared to tinker with it, this is not the right kit. The combination of the Blem receiver condition and the platform-specific build demands makes this kit best suited for experienced AR-45 builders who know what they are getting into and are equipped to work through it.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. This kit requires customer-supplied parts and platform-specific tuning for reliable operation. Recommended for experienced AR-45 builders only. Blem receiver may include minor scratches, forging marks, finish color variations, or coating imperfections that do not affect function.