Does the Radian Weapons AX556 Billet work with the Aero Precision M4E1 Threaded Upper 18"?
Lower Receiver
Radian Weapons AX556 Billet
from $514.95
Upper Receiver
Aero Precision M4E1 Threaded Upper 18" 6.5 Grendel SS Barrel
from $654.99
Radian lower and Aero Precision upper compatibility
Yes, they fit
The Radian Weapons AX556 Billet works with the Aero Precision M4E1 Threaded Upper 18" 6.5. Our compatibility rules found no conflict between them.
This exact setup is in a real GunPartPicker build.
Counted from real GunPartPicker builds: parts lists people put together while planning to buy.
Checked by the same rules the AR builder runs on every part you add: caliber, frame size, receiver pattern, thread pitch and gas length.
Fit is judged from the specs retailers list, which can be missing or wrong. Confirm with the manufacturer before you buy, and have a qualified gunsmith check any build before you fire it.
How often builders pair the Radian lower and Aero Precision upper
Backed by tens of thousands of qualified builds that have both a lower and an upper.
Share of builds with the Radian Weapons AX556 Billet and any upper
- This pairAero Precision M4E1 Threaded Upper 18" 6.54%
- CMMG Resolute MK3 8.6 Blackout 16.1 inch 1-3Does not fit4%
Radian Weapons AX556 Billet
- Of lower picks
- 0.1%
- Median paid
- $490
Aero Precision M4E1 Threaded Upper 18"
Not in enough builds yet to report.
How we count ⌄
These shares come from GunPartPicker's build data: real parts lists people put together while planning a purchase, not sales or surveys. A build counts a part only when it is the final pick for its slot, so parts that were swapped out never count. Fit never comes from these numbers; it comes from our compatibility rules alone.
Frequently built with the Radian lower and Aero Precision upper
The part builders pick most often in each slot alongside these two, checked against both. Parts that conflict are left out.
Pistol Grip
Charging Handle
Bolt Carrier Group
Radian Weapons Enhanced Nitride
Fits, check note
Handguard
Muzzle Device
Gas Block
Barrel
Buffer Tube Assembly
Radian Weapons AX556 Billet vs Aero Precision M4E1 Threaded: specs and prices
| Radian Weapons AX556 Billet | Aero Precision M4E1 Threaded | |
|---|---|---|
| Best price | $514.95 at Brownells | $654.99 at Dirty Bird Industries |
| Stores | 6 of 9 in stock | 0 of 1 in stock |
| Assembly | Stripped | Complete |
| Platform | AR-15 | AR-15 |
| Caliber | Multi | 6.5 Grendel |
| Trigger Pin | .154 | n/a |
| Finish | Hardcoat Anodized | n/a |
| Color | Black | n/a |
| Gas System Length | n/a | Rifle |
| Receiver Type | n/a | M4E1 |
| Length | n/a | 18 |
Both for $1169.94 at today's best prices.
Today's best prices and 90 day price history
Every store we track for each part, cheapest in stock first. Prices are checked through the day.
Price history, last 90 days
- Radian Weapons AX556 Billet: lowest $514.95 on Jul 5, highest $533.99 on Sep 12 over the last 90 days.
- Aero Precision M4E1 Threaded Upper 18": lowest $654.99 on Jul 5, highest $654.99 on Jul 5 over the last 90 days.
Upper Receivers frequently paired with the Radian Weapons AX556 Billet
Most picked next to it in real builds. Only parts our rules say fit the Radian Weapons AX556 Billet are listed.
Lower Receivers most paired with Aero Precision uppers
The Aero Precision M4E1 Threaded Upper 18" is not in enough builds yet, so these are the most picked next to any Aero Precision upper. Only parts our rules say fit the Aero Precision M4E1 Threaded Upper 18" are listed.
