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

The way its supposed to be


A+++ service, prices, and lightning shipping. It doesn't get any better than this!

Great for me!


Actually bought 2 of these to replace the 1/9 barrels on my 2 M4gery rifles. They look good, nice crowns but haven't had a chance to shoot them yet.

great product


amazing barrel but the main thing is primary arms shipping i cant get over how fast they are . i find my self getting frustrated with other websites because none of them can ship like pa. all i can say is customer for life!!

Very Nice Barrel!


At first I almost lost it when I opened the box and on the outside of the packaging it said it was a Mid Length Barrel... Not that I have anything against Mid Systems, but I'd ordered the carbine gas tube. So thankfully when I opened it up and saw it was a carbine length, i was very happy! My question is this though, did the person who packed my order know it was mis labeled, or did they make a mistake and send the wrong one only to end up being the right one? I guess some things are unexplainable... Anyways, awesome barrel!

ST-16" M4 LE-5.56


Barrel looks good, haven't gotten a chance to shoot it yet so I can't give any statement as to accuracy at this time.

Spikes Tactical Barrel ST-16" M4 LE-5.56


Barrel was perfect just as described super fast shipping will buy here againthank you Primary Arms

Really nice barrel


Fastest shipping and it is a very great barrel for the price. Fit right up and it had a lot of oil all over the barrel in the package that it was in



First off, great shipping from primary. They got this to me in only a few days. I love that they have a real time inventory, so you know your not wasting your time looking at something, only to find out they don't have it. And I checked around, prices can't be beat here. Thanks primary arms.

Outstanding experience


Great experience with Primary Arms! This was my first order, and I received it in 3 days. I will definitely buy from them again.

Very nice barrel


Great finish, no problems installing. Still need to shoot it.