Does the STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL work with the FailZero AR9?

STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL MLOK RAIL

Upper Receiver

STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL MLOK RAIL

from $498.56

FailZero AR9, 9mm BCG, Black Nitride

Bolt Carrier Group

FailZero AR9

from $132.03

Stern Defense upper and FailZero bolt carrier group compatibility

Yes, they fit

The STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL MLOK RAIL works with the FailZero AR9. 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 Stern Defense upper and FailZero bolt carrier group

Backed by thousands of qualified builds that have both an upper and a bolt carrier group.

Bolt Carrier Groups builders put on the STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL

Share of builds with the STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL and any bolt carrier group

Upper Receivers builders put under the FailZero AR9

Share of builds with the FailZero AR9 and any upper

  • STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL

    Of upper picks
    0%
    Median paid
    $499

  • FailZero AR9

    Of bolt carrier group picks
    0.3%
    Median paid
    $131
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 Stern Defense upper and FailZero bolt carrier group

The part builders pick most often in each slot alongside these two, checked against both. Parts that conflict are left out.

Charging Handle

Lower Receiver

Trigger

Pistol Grip

Suppressor

Optic

Barrel

Stock & Brace

Handguard

STERN DEFENSE MOD5 UPPER 9MM vs FailZero AR9: specs and prices

STERN DEFENSE MOD5 UPPER 9MMFailZero AR9
Best price$498.56 at BattleHawk Armory$132.03 at BattleHawk Armory
Stores1 of 1 in stock4 of 4 in stock
AssemblyCompleten/a
PlatformAR-9n/a
Caliber9mmn/a
Length8.5n/a
Cartridgen/a9mm
Stylen/aPistol Caliber Blow Back Carrier
Finishn/aNitride

Both for $630.59 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.

STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL MLOK RAIL

FailZero AR9

Price history, last 90 days

  • STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL: lowest $498.56 on Jul 5, highest $498.56 on Jul 5 over the last 90 days.
  • FailZero AR9: lowest $132.03 on Jul 5, highest $179.99 on Aug 28 over the last 90 days.

Bolt Carrier Groups frequently paired with the STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL

Most picked next to it in real builds. Only parts our rules say fit the STERN DEFENSE MOD5 UPPER 9MM 8.5IN BBL are listed.

Upper Receivers frequently paired with the FailZero AR9

Most picked next to it in real builds. Only parts our rules say fit the FailZero AR9 are listed.