Does the Radian Weapons AX556 Billet work with the Knights Armament CQB Mod 2 11.5" Urx 4?
Lower Receiver
Radian Weapons AX556 Billet
from $514.95
Upper Receiver
Knights Armament CQB Mod 2 11.5" Urx 4 M-LOK
from $1962.99
Radian lower and Knights Armament upper compatibility
Yes, they fit
The Radian Weapons AX556 Billet works with the Knights Armament CQB Mod 2 11.5" Urx 4 M-LOK. 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 Knights Armament 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 pairKnights Armament CQB Mod 2 11.5" Urx 4 M-LOK4%
Share of builds with the Knights Armament CQB Mod 2 11.5" Urx 4 and any lower
- This pairRadian Weapons AX556 Billet5%
Radian Weapons AX556 Billet
- Of lower picks
- 0.1%
- Median paid
- $490
Knights Armament CQB Mod 2 11.5" Urx 4
- Of upper picks
- 0.1%
- Median paid
- $1963
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 Knights Armament 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
Stock & Brace
Bolt Carrier Group
Radian Weapons Enhanced Nitride
Fits both
Handguard
Knights Armament Urx 4 M-LOK 10.75"
Fits both
Muzzle Device
Gas Block
Barrel
Buffer Tube Assembly
Radian Weapons AX556 Billet vs Knights Armament CQB Mod 2: specs and prices
| Radian Weapons AX556 Billet | Knights Armament CQB Mod 2 | |
|---|---|---|
| Best price | $514.95 at Brownells | $1962.99 at BattleHawk Armory |
| Stores | 6 of 9 in stock | 0 of 2 in stock |
| Assembly | Stripped | Stripped |
| Platform | AR-15 | AR-15 |
| Caliber | Multi | 5.56 NATO |
| Trigger Pin | .154 | n/a |
| Finish | Hardcoat Anodized | n/a |
| Color | Black | n/a |
| Length | n/a | 11.5 |
Both for $2477.94 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.
- Knights Armament CQB Mod 2 11.5" Urx 4: lowest $1962.99 on Jul 5, highest $2099.99 on Jul 6 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 frequently paired with the Knights Armament CQB Mod 2 11.5" Urx 4
Most picked next to it in real builds. Only parts our rules say fit the Knights Armament CQB Mod 2 11.5" Urx 4 are listed.
