Does the Fortis Billet M4 Upper Stripped work with the FailZero Fail Zero 6.5 Grendel Type II?

Fortis Billet M4 Upper Stripped for AR15 223 Rem, 556 NATO - UBilletM4

Upper Receiver

Fortis Billet M4 Upper Stripped

from $189.95

Fail Zero 6.5 Grendel Type Ii Ar-15 Bolt Carrier Group - No Hammer

Bolt Carrier Group

FailZero Fail Zero 6.5 Grendel Type II

from $144.51

Fortis Manufacturing upper and FailZero bolt carrier group compatibility

Yes, they fit

The Fortis Billet M4 Upper Stripped works with the FailZero Fail Zero 6.5 Grendel Type II. Our compatibility rules found no conflict between them.

This exact setup has been built more than once on GunPartPicker.

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 Fortis Manufacturing 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 Fortis Billet M4 Upper Stripped

Share of builds with the Fortis Billet M4 Upper Stripped and any bolt carrier group

Upper Receivers builders put under the FailZero Fail Zero 6.5 Grendel Type II

Share of builds with the FailZero Fail Zero 6.5 Grendel Type II and any upper

  • Fortis Billet M4 Upper Stripped

    Of upper picks
    0.1%
    Median paid
    $167

  • FailZero Fail Zero 6.5 Grendel Type II

    Of bolt carrier group picks
    0.1%
    Median paid
    $151
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 Fortis Manufacturing 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.

Lower Receiver

Gas Block

Charging Handle

Pistol Grip

Trigger

Stock & Brace

Suppressor

Handguard

Barrel

Optic

Fortis Billet M4 Upper vs FailZero Fail Zero 6.5 Grendel: specs and prices

Fortis Billet M4 UpperFailZero Fail Zero 6.5
Best price$189.95 at Optics Planet$144.51 at BattleHawk Armory
Stores4 of 5 in stock5 of 6 in stock
AssemblyStrippedn/a
PlatformAR-15n/a
Caliber.223 Wylden/a
Receiver TypeBilletn/a
Cartridgen/a6.5 Grendel
Stylen/aM16 Bolt Carrier
Finishn/aNickel Boron

Both for $334.46 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.

Fortis Billet M4 Upper Stripped

FailZero Fail Zero 6.5 Grendel Type II

Price history, last 90 days

  • Fortis Billet M4 Upper Stripped: lowest $167.16 on Jul 5, highest $210.99 on Sep 27 over the last 90 days.
  • FailZero Fail Zero 6.5 Grendel Type II: lowest $140.70 on Jul 5, highest $190.99 on Aug 4 over the last 90 days.

Bolt Carrier Groups frequently paired with the Fortis Billet M4 Upper Stripped

Most picked next to it in real builds. Only parts our rules say fit the Fortis Billet M4 Upper Stripped are listed.

Upper Receivers frequently paired with the FailZero Fail Zero 6.5 Grendel Type II

Most picked next to it in real builds. Only parts our rules say fit the FailZero Fail Zero 6.5 Grendel Type II are listed.