Does the Spike's Tactical Spikes Tactical Rare work with the Stern Defense SD 4in MOD4 M-LOK 4in?

Lower Receiver
Spike's Tactical Spikes Tactical Rare Breed Crusader
from $436.50

Upper Receiver
Stern Defense SD 4in MOD4 M-LOK 4in Barrel 9mm SDINBRLKK
from $419.27
Spike's Tactical lower and Stern Defense upper compatibility
Yes, they fit
The Spike's Tactical Spikes Tactical Rare Breed works with the Stern Defense SD 4in MOD4 M-LOK 4in Barrel 9mm. 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 Spike's Tactical lower and Stern Defense upper
Backed by tens of thousands of qualified builds that have both a lower and an upper.
Share of builds with the Spike's Tactical Spikes Tactical Rare and any upper
- This pairStern Defense SD 4in MOD4 M-LOK 4in Barrel 9mm29%
Share of builds with the Stern Defense SD 4in MOD4 M-LOK 4in and any lower
- This pairSpike's Tactical Spikes Tactical Rare Breed29%
Spike's Tactical Spikes Tactical Rare
- Of lower picks
- 0%
- Median paid
- $437
Stern Defense SD 4in MOD4 M-LOK 4in
- Of upper picks
- 0%
- Median paid
- $419
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 Spike's Tactical lower and Stern Defense upper
The part builders pick most often in each slot alongside these two, checked against both. Parts that conflict are left out.
Bolt Carrier Group

Stern Defense Nickel Boron 9mm
Fits both
Pistol Grip
Stock & Brace
Spike's Tactical Spikes vs Stern Defense SD 4in MOD4: specs and prices
| Spike's Tactical Spikes | Stern Defense SD 4in MOD4 | |
|---|---|---|
| Best price | $436.50 at KY Gun Company | $419.27 at Optics Planet |
| Stores | 0 of 1 in stock | 1 of 1 in stock |
| Assembly | Stripped | Complete |
| Platform | AR-9 | AR-9 |
| Caliber | 9mm | 9mm |
| Finish | Hardcoat Anodized | n/a |
| Color | Black | n/a |
| Length | n/a | 4 |
Both for $855.77 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
- Spike's Tactical Spikes Tactical Rare: lowest $436.50 on Jul 5, highest $436.50 on Jul 5 over the last 90 days.
- Stern Defense SD 4in MOD4 M-LOK 4in: lowest $376.96 on Jul 5, highest $419.27 on Jul 12 over the last 90 days.
Upper Receivers frequently paired with the Spike's Tactical Spikes Tactical Rare
Most picked next to it in real builds. Only parts our rules say fit the Spike's Tactical Spikes Tactical Rare are listed.
Lower Receivers frequently paired with the Stern Defense SD 4in MOD4 M-LOK 4in
Most picked next to it in real builds. Only parts our rules say fit the Stern Defense SD 4in MOD4 M-LOK 4in are listed.


Bravo Company Manufacturing
Fits, check noteCheck fit












