Does the Primary Weapons Systems MK1 5.56x45mm AR work with the Daniel Defense MK18 5.56 Group?
Lower Receiver
Primary Weapons Systems MK1 5.56x45mm AR Lower
Upper Receiver
Daniel Defense MK18 5.56 Group
from $1279.99
Primary Weapon Systems lower and Daniel Defense upper compatibility
Yes, they fit
The Primary Weapons Systems MK1 5.56x45mm AR Lower works with the Daniel Defense MK18 5.56 Group. Our compatibility rules found no conflict between them.
No one has built this exact setup yet, but Primary Weapon Systems lowers with Daniel Defense uppers are a common pairing.
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 Primary Weapon Systems lower and Daniel Defense upper
Backed by tens of thousands of qualified builds that have both a lower and an upper.
Share of builds with the Daniel Defense MK18 5.56 Group and any lower
Primary Weapons Systems MK1 5.56x45mm AR
Not in enough builds yet to report.
Daniel Defense MK18 5.56 Group
- Of upper picks
- 0.4%
- Median paid
- $1412
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 Primary Weapon Systems lower and Daniel Defense upper
The part builders pick most often in each slot alongside these two, checked against both. Parts that conflict are left out.
Charging Handle
Radian Raptor & Talon Safety Selector Combo
Unconfirmed
Bolt Carrier Group
Daniel Defense Bolt/carrier Group
Fits both
Stock & Brace
Suppressor
Pistol Grip
Primary Weapons Systems MK1 vs Daniel Defense MK18 5.56 Group: specs and prices
| Primary Weapons Systems MK1 | Daniel Defense MK18 5.56 | |
|---|---|---|
| Best price | n/a | $1454.00 at BattleHawk Armory |
| Stores | n/a | 1 of 5 in stock |
| Assembly | Complete | Complete |
| Platform | AR-15 | AR-15 |
| Caliber | 5.56 NATO | 5.56 NATO |
| Trigger Pin | .154 | n/a |
| Finish | Hardcoat Anodized | n/a |
| Color | Black | n/a |
| Gas System Length | n/a | Pistol |
| Receiver Type | n/a | A4 |
| Length | n/a | 10.3 |
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
- Daniel Defense MK18 5.56 Group: lowest $1279.99 on Sep 12, highest $1527.00 on Sep 2 over the last 90 days.
Upper Receivers most paired with Primary Weapon Systems lowers
The Primary Weapons Systems MK1 5.56x45mm AR is not in enough builds yet, so these are the most picked next to any Primary Weapon Systems lower. Only parts our rules say fit the Primary Weapons Systems MK1 5.56x45mm AR are listed.
Lower Receivers frequently paired with the Daniel Defense MK18 5.56 Group
Most picked next to it in real builds. Only parts our rules say fit the Daniel Defense MK18 5.56 Group are listed.
