FAXON DUTY SERIES LIGHT TAPERED 10.5" 10MM SAAMI BLOWBACK AR15 BARREL

Rifle Barrels › Pistol Caliber Carbine › 10mm Auto › 10.5″ Light Tapered, Blowback  |  Works with: 10mm PCC BCG • 5/8x24 HUB adapter • AR-15 upper

Why a 10.5″ 10mm PCC

10mm Auto is what a pistol-caliber carbine shooter chooses when 9mm is not enough: a .400″ bullet at 37,500 psi that leaves a 5″ pistol at 1,200 to 1,250 fps with 180 gr and picks up another 100 to 200 fps from a 10.5″ barrel, which puts it in .357 Magnum carbine territory with more bullet. That makes it the PCC that hunts, the PCC for hogs and black bear inside 100 yards where a 9mm is a range gun, and the pistol or SBR that protects a camp or a truck with a Glock 20 magazine of 15 rounds. Ten and a half inches is the length that gets almost all of the velocity the cartridge has to give, because a pistol cartridge burns out early, and it keeps the gun short enough to shoulder in a vehicle. Faxon makes the same barrel in 16″ for a rifle with no paperwork; it adds about 50 fps and five and a half inches.

The Light Tapered profile is Faxon’s PCC contour, and it is built for what a blowback gun needs. A blowback barrel does not carry a gas block, so there is nothing to step down to; it needs a full-diameter journal to seat in the upper, a collar to index against, and enough wall around the chamber for a 37,500 psi cartridge, and beyond that every ounce is dead weight on the front of a gun that gets pointed fast. So the barrel runs a 1.000″ receiver journal with an indexing pin, a .980″ collar, a short 15° taper, and then a straight .750″ body to a .725″ muzzle shoulder and 5/8x24 threads. At 1.08 lb it weighs what Faxon’s 10.5″ 9mm does within an ounce, and it takes Faxon’s 10mm PCC blowback bolt carrier group, which was built alongside it with a removable weight so the gun can be tuned to the ammunition instead of the other way around.

What “Duty Series” Means

Duty Series is Faxon’s 4150 CMV line: the M4/M16 barrel alloy, salt-bath QPQ nitrided inside and out. 4150 carries about 0.50% carbon plus vanadium, which gives it more strength and wear resistance at temperature than 4140, and nitride adds a hard, corrosion-resistant surface to the bore and exterior without plating anything, and it adds virtually nothing to the surface: a few ten-thousandths of an inch, roughly a tenth the width of a human hair. It is the right combination for a barrel that will be shot hard, carried in the weather, and cleaned when there is time.

What’s in the Box

How It’s Made

Every Duty Series barrel is made start to finish in Faxon’s Greater Cincinnati plant, on Faxon’s machines, to Faxon’s prints. This is the routing for this barrel.

1. Drill and pull-ream 4150 CMV bar is gun-drilled, then pull-reamed from the chamber end to a .3905″ bore held to ±.001″, with a 32 Ra maximum finish checked on a profilometer.
2. Button rifle A carbide button is pulled through from the chamber end to form six grooves, right-hand, one turn in 16 inches, to a .400″ groove diameter. Bore and groove are air-gauged.
3. Stress relieve and qualify The rifled blank is stress relieved before it becomes a finished barrel, then the OD is qualified true to the bore so every later cut references the same axis.
4. Turn the breech end The 1.000″ receiver journal is turned to .9987″ +0/−.0008 and checked on every barrel, with the indexing flange and the .980″ collar behind it.
5. Turn the Light Tapered profile The 15° taper and the straight .750″ body are turned true to the bore, the .725″ muzzle shoulder is cut, and the 5/8x24 muzzle is threaded, gauged, and crowned at 11°.
6. Chamber and ramp The 10mm Auto chamber is cut to a 10mm GO gauge and checked on every barrel, chamber surfaces are held to a 20 Ra finish, and the Glock®-magazine feed ramp is machined into the breech face.
7. MPI and nitride The machined barrel is 100% wet magnetic-particle inspected for surface and near-surface flaws, then salt-bath QPQ nitrided inside the bore and out, hardening the surface while adding virtually nothing to it.
8. Pin and mark After nitride, the .125″ indexing pin is pressed in and the Faxon shield and order number are laser-engraved on the chamber journal with “10MM 1-16T” ahead of it.

What Reviewers and Owners Say

Voted Favorite Aftermarket Barrel by Shooting Sports Retailer every year since 2022 — the Gold Award, the top honor in the category. Faxon also took the Tactical Retailer Gold Award in the same category in 2025. Here is what buyers have said about Faxon PCC barrels.

The 10.5″ 10mm is the newer of Faxon’s two 10mm barrels and has no reviews on FaxonFirearms.com yet; the 16″ 10mm is rated 5.0 here, Faxon’s 10mm Light Tapered barrels are rated 5.0 across 2 reviews at OpticsPlanet, and the 9mm version of this barrel is rated 5.0 across 19 reviews on the 16″ and 4.0 across 4 on the 10.5″.

Build It Out: Faxon Parts That Fit This Barrel

A blowback PCC is barrel, bolt carrier, upper, and rail. Everything below is made or specified to fit this barrel the first time.

Duty Series 10.5″ 10mm Blowback FAQs

Is this a SAAMI 10mm Auto chamber, and will it run full-power loads?

Yes, a SAAMI 10mm Auto chamber, cut to a 10mm GO gauge and checked on every barrel. It runs the whole range, from 155 gr competition loads through 180 gr defensive and 200 to 220 gr hard-cast hunting loads at full SAAMI pressure (37,500 psi). Because the gun is blowback, what changes with hot ammunition is not the barrel but the bolt: heavy loads want the full carrier weight installed and a heavy buffer; light loads may want the weight removed. Faxon’s 10mm PCC BCG has a removable weight for exactly that.

Does this barrel need a gas block or gas tube?

No. A blowback 10mm PCC has no gas system at all: the cartridge pushes the bolt straight back against the carrier mass and the buffer spring, and the barrel has no gas port, no journal, and no block. That is why the profile can run a straight .750″ from the taper to the muzzle, and why any free-float handguard fits. What the gun needs instead is a blowback bolt carrier group built for 10mm and a buffer heavy enough for the load.

What upper, lower, bolt, and magazines does it need?

The barrel seats in any mil-spec AR-15 upper receiver: its 1.000″ receiver journal and .125″ indexing pin fit the receiver bore and pin slot the way a 5.56 barrel extension does, and the feed ramp is machined into the barrel for Glock® 10mm magazines. The lower must be a 10mm/.45 PCC lower cut for Glock 20-pattern magazines, which are wider than 9mm Glock magazines and will not fit a 9mm PCC lower. The bolt carrier is Faxon’s 10mm PCC blowback BCG, Glock-pattern, full-mass, with a removable weight, built alongside this barrel; a 5.56 or 9mm carrier will not work. Magazines are Glock 20 or 10mm PCC-pattern.

How fast does 10mm leave a 10.5″ barrel, and what is it good for?

A 180 gr load rated at 1,200 to 1,250 fps from a 5″ pistol leaves a 10.5″ barrel at roughly 1,350 to 1,450 fps, depending on the load, with 750 to 850 ft-lb, and a 200 gr hard-cast hunting load at about 1,250 to 1,350. That is .357 Magnum carbine energy with a heavier, wider bullet, which is why 10mm PCCs are used for hogs, deer, and black bear inside 100 yards, for bear defense in a pack, and for home and vehicle defense with 15 rounds in a Glock 20 magazine. The 16″ adds about 50 fps; a pistol cartridge is nearly burned out by 10.5″.

What is the Light Tapered profile?

Faxon’s PCC contour. A blowback barrel carries no gas block, so it does not need the steps a rifle barrel does; it needs a full-diameter journal to seat in the upper, a collar to index against, and enough wall around a 37,500 psi chamber. So the barrel runs a 1.000″ receiver journal, a .980″ collar, a short 15° taper, and a straight .750″ body to a .725″ muzzle shoulder. Everything past the collar is as light as a .400″ bore allows, which is why a 10.5″ 10mm barrel weighs 1.08 lb and the gun balances at the magazine well.

Will it work with a suppressor?

Yes, with the right can. The 5/8x24 muzzle takes any .40- or .45-caliber-rated pistol suppressor, direct-thread or on Faxon’s 5/8x24 HUB adapter; a .30-cal or 9mm can will not pass a .400″ bullet. Blowback guns run dirtier suppressed than gas guns because the action opens under pressure, so expect more gas at the ejection port, and note that 10mm has no common subsonic factory loads, so a suppressed 10mm is quieter, not quiet.

What does 4150 CMV mean?

Chrome-moly-vanadium steel with about 0.50% carbon, the alloy the M4 and M16 barrel specification calls for. The higher carbon and the vanadium give it more strength and wear resistance at temperature than 4140, which matters on a barrel that holds a 37,500 psi cartridge and gets shot fast.

Is the nitride inside the bore?

Yes. Salt-bath QPQ nitride is a diffusion treatment, not a plating, so it hardens the surface of the bore and the exterior while adding virtually nothing to it: the surface grows by a few ten-thousandths of an inch, .0002–.0004″, roughly a tenth the width of a human hair or about the diameter of a single red blood cell. It also gives the barrel its corrosion resistance and matte black finish.

Can I put a 10.5″ barrel on my AR?

A barrel under 16″ makes the firearm either a pistol or a short-barreled rifle under federal law. Build it on a lower that has only ever been a pistol, or on a lower registered as an SBR with an approved Form 1 or Form 4, and check your state law before you buy. If you want a rifle with no paperwork, Faxon makes this barrel in 16″. Faxon cannot advise on your specific configuration.

Where is it made, and what is the warranty?

Made in Greater Cincinnati, Ohio, from bar stock to finished barrel, and covered by the Faxon Lifetime Guarantee.

Dimensions are from the Faxon engineering print and inspection sheets for this SKU; weight is nominal. Bolt carrier group, buffer, and muzzle device sold separately. Owner reviews are quoted as written from FaxonFirearms.com product reviews. Award: Shooting Sports Retailer Choice Awards, Favorite Aftermarket Barrel, Gold. Covered by the Faxon Lifetime Guarantee.