California and shipping
- Status: Firearm. A stripped or complete lower receiver requires an FFL transfer.
- Delivery: Ships to WBT in La Mesa or to the California gun store you choose. DROS and the 10-day wait are completed at pickup.
- Finishing the build: Build it featureless or with a fixed-magazine kit to keep it California-legal. We stock both and can do the work for you.
- Learn more: Featureless or fixed magazine: which fits your build · FAQ
About this lower receiver
Aero Precision M4E1 5.56 NATO Assem Uppr Receiver M4 16'' Barrel Mid-length Black is a lower receiver. Finish: Black.
Manufacturer details
Aero Precision’s M4E1 5.56mm Mid-Length Upper Receiver comes fully assembled, lacking only a bolt/carrier group and charging handle - the two components most often replaced by customizers. "Mid-Length" refers to the gas tube, which is longer than the standard carbine tube to slow down gas velocity and actually improve reliability in cycling. This is actually a carbine upper, available with either a military 14.5" or civilian 16" barrel (see Gun Tech Note below).
The core of the M4E1 5.56mm Mid-Length Upper Receiver is Aero’s forged M4E1 receiver that combines the looks of a machined receiver with "mil-spec" parts compatibility (including BCG and charging handle). It’s mated to Aero’s latest Gen 2 Enhanced M-LOK Handguard to form a monolithic assembly with a full-length Picatinny top rail, and plenty of attachment points for M-LOK-accessories. QD sling swivel sockets at the 3/6/9 o’clock positions.
The extended handguard covers the low-profile gas block. Texturing milled into the flats gives you an enhanced grasping surface - plus, it adds to your gun’s unique appearance.
Features
- Forged 7075 T6 aluminum receiver, Mil 8625 Type 3 Class 2 hardcoat anodized
- Ejection port cover & forward assist installed
- 4150 chrome-moly-vanadium barrel, 1-7" rifling, black QPQ finish
- Chambered for 5.56x45 NATO; accepts .223 Remington, too
- MID-LENGTH gas system
Specifications
- Brand: Aero Precision
- Finish / color: Black
- Fits: AR-15
- UPC: 815421023305
Buying from WBT Guns
- Payment: Pay in full, put 50% down with the balance due in 14 days, or finance with Credova.
- Paperwork: Firearm Safety Certificate, DROS and California's 10-day waiting period apply to receivers. We handle each step with you at pickup.
- Questions: Call (619) 667-9453 or email sales@wbtguns.com. FAQ
WBT Guns is family-owned in La Mesa, California, and has configured firearms for California buyers since 2012.
A note on accuracy. We work hard to keep every listing correct, but specifications, images and compliance details come from many sources and can contain errors or change without notice. Images may show a configuration that is not California-legal. If a detail on this page matters to your decision, call us and we will confirm it against the actual firearm before you order. The compliance information here is general in nature and is not legal advice; California and local laws change, and the configuration described is confirmed at the time of sale. All sales are subject to applicable federal, state and local law and to the buyer's eligibility to purchase.
