Spike's Tactical 16" 5.56 M4 Carbine Length AR-15 Barrel

Manufactured by Spike's Tactical
SKU: SB51605-M4
MPN: SB51605-M4
Manufactured by Spike's Tactical
34 Reviews
$211.50 $287.96

In Stock

Standard orders will ship out 2 business days if ordered by 3:30 pm CST, Monday-Friday. FFL orders will ship within 5 business days or less as long as we have the information for the transfer destination.



The barrel is one of the most critical components of your build. We only offer high quality barrels so you can be confident that your rifle will be off to a good start with whichever you decide.


  • MIL-STD-171 phosphate finish on the barrel exterior.
  • 1:7 twist rate.
  • 1/2x28 thread pitch.
  • MIL-STD-171 hard chrome bore 5.56mm NATO chamber.
  • All chambers are checked for head spacing before and after plating.
  • High pressure tested and magnetic particle inspected.
  • Threads are cut concentric to the bore.
  • Uses .750" gas block.
  • Weight: 28.0 oz.
  • Spike's Tactical lifetime warranty.

See More


Barrel CoatingManganese Phosphate
Barrel ContourM4
Barrel Length16
Barrel LiningChrome
Barrel Material41V50 Chrome Moly Vanadium Steel
BrandSpike's Tactical
Caliber Gauge5.56 NATO
Feed RampsM4
Gas Seat Diameter.750
Gas System LengthCarbine
Manufacturer.Spike's Tactical
Thread Pattern1/2 X 28
Twist Rate1:7
Weight28 Oz

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see www.p65warnings.ca.gov

Ratings & Reviews

34 reviews

  • 4 stars
  • 0 reviews
  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews
  • 1 star
  • 0 reviews

Awesome barrel.


Great fit, finish and accuracy.

spikes barrel@ primary arms


I called and got a real person and not only did they answer the questions that I had the guy went to the warehouse and pulled the barrel and verified it was exactly what I needed, which is awsome since some places wouldn't even answer the phone. it shipped and arrived really fast. great service and good people if you are thinking about buying from them don't even think twice about it just call. I would not hesitate to buy from them if I build another AR. THANKS AGAIN!!!

Spikes makes a good product


Its a Spikes, and like everything else I have seen from them they live up to their name. Great barrel at a great price. I haven't had any issues with it.

Spike barrel


Love it. Got here in no time.

Spikes Barrel


My experience with Primary Arms has always been great: Only quality products, fair pricing and quick delivery. It just doesn't get any better

Great product & incredible service


My order shipped within hours of me placing it. The product was delivered properly packaged. The ST16 has a very quality look about it, and ran great with no issues to report.

good barrel


nice looking barrel. just what i needed... in stock and quick delivery!

Fantastic service!


Product shipped promptly and was exactly as described on site. Thanks Primary Arms!

Spikes Barrels and Primary Arms, Easy Button


Spikes ST-16 M4 barrel, excellent finish, and easy to install, gas block fit perfect, and even with the chrome lined barrel, less than 2 MOA with LC Ball ammo.Primary arms, I signed up for an email alert, got the message the barrels were in stock, ordered, and 3 days later I had the barrel, 5 stars and 5 thumbs UP. Big thanks

Great barrel Great Customer Service!


The spikes st-16 M4 barrel is exactly what you would expect from spikes! Quality at an affordable price and one heck of a shooter for the money. Groups of 1-1.25 can be expected with this barrel at 100 yards with ease.