Budget AR-15 Starter Build

This build guide walks you through assembling a reliable, functional AR-15 for under $520 using our Beginner builder mode. Instead of selecting 15+ individual components, you pick two halves — a Complete Upper and a Complete Lower — snap them together, and you have a working rifle. Add an optic, a sling, and a magazine, and you're range-ready.

Total cost: $516.88. Here's what's in the build:

PSA Complete Upper Receiver ($149.99) — Palmetto State Armory's complete upper comes with a 16-inch barrel, M4 feed ramps, bolt carrier group, and charging handle pre-installed. One unit, ready to pin onto any mil-spec lower. PSA has shipped millions of these — they work.

Anderson AM-15 Complete Lower Receiver ($149.00) — Anderson is the most affordable name in complete lowers. This comes with the fire control group (trigger, hammer, disconnector), pistol grip, buffer tube assembly, and stock already assembled. Mate it with the PSA upper using two takedown pins and you have a functioning rifle.

[SIG Sauer Romeo5](/part/455) Red Dot ($139.99) — The Romeo5 is the consensus best budget red dot. 2 MOA dot, MOTAC (motion-activated on/off), shake-awake technology, and it comes with both a low mount and a 1.41-inch co-witness mount. Runs 40,000+ hours on a single CR2032 battery. It's been proven on duty guns and competition rifles alike.

[Magpul MS4 Dual QD Sling](/part/2877) ($64.95) — Converts between single-point and two-point configuration. QD swivel mounts let you clip on and off quickly. A sling is the most underrated accessory on a rifle — it's your holster.

[Magpul PMAG 30 Gen M2 MOE](/part/461) ($12.95) — The industry standard magazine. Reliable, affordable, and available everywhere. The anti-tilt follower and stainless steel spring ensure consistent feeding.

1. 1.Go to the AR-15 builder and select Beginner tier
2. 2.Click Complete Upper — search for "PSA" or browse by price
3. 3.Click Complete Lower — pick the Anderson AM-15
4. 4.Watch the dependency engine auto-disable barrel, gas system, BCG, charging handle, trigger, grip, buffer, and stock slots — these are all included in your upper and lower
5. 5.Your combined rifle price appears at the top
6. 6.Click + Add Accessories to pick your optic, sling, and magazine
7. 7.Save your build and share it

The Beginner tier filters out stripped receivers and individual small parts so you only see complete assemblies. This prevents the common mistake of buying a stripped upper (no barrel) thinking it's a complete rifle.

This build is intentionally simple. Once you've shot it and understand what you want to change, switch to Intermediate tier in the builder to see individual component slots. Common first upgrades:

Trigger — The mil-spec trigger in the Anderson lower is functional but heavy (~7 lbs). A LaRue MBT-2S ($99) or Rise Armament RA-140 ($89) drops pull weight to 3.5 lbs and dramatically improves accuracy.

Handguard — If your PSA upper came with a standard plastic handguard, upgrading to a free-float M-LOK rail (like the Aero Precision Atlas or Midwest Industries) improves accuracy and gives you mounting points for a weapon light.

Weapon Light — A Streamlight ProTac HL-X ($100) or Cloud Defensive REIN Micro ($280) is essential if this rifle has any defensive purpose.

Charging Handle — The mil-spec charging handle works but an ambidextrous option like the Radian Raptor ($70) makes manipulations faster and easier.

Use the Pro tier builder to see every possible slot and fine-tune your rifle one component at a time.