Custom Remington TAC-14 Build

It is no secret that I am completely enamored with my Remington TAC-14 and Mossberg 590 SHOCKWAVE.  You wouldn’t think a guy who writes a blog called and devotes hundreds of hours a year to precision rifles would be into a pistol grip 14″ 12-gauge firearm, but I am.  It may be the antithesis of the precision rifle, it is a fun gun that delivers a heavy payload.  What’s more is by adding the GATOR shot diverter, a new version of the shotgun duckbill, it can spray impressive patterns of number 4 buckshot downrange.

As good as the TAC-14 is from the factory, I couldn’t help but try to make it a little better.  In this post, I’ll customize the TAC-14 to enhance it’s performance.  For this project, I’ll be:

  • Installing an interchangeable choke tube system
  • Installing Wilson Combat Ghost ring sights
  • Installing a Wilson Combat one-shot extension
  • Installing a Wilson Combat oversized safety
  • Coating all metal surfaces in Concrete Cerakote Elite

You’ll note the heavy reliance on Wilson Combat parts.  This is because I’ve had great luck with their products, they certainly seem to have the Remington 870 platform figured out and are always my first stop for aftermarket 870 parts.

I ordered the following tools, parts and supplies from Brownells to complete this project:

The contents of are produced for informational purposes only and should be performed by competent gunsmiths only. and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Any modifications made to a firearm should be made by a licensed gunsmith. Failure to do so may void warranties and result in an unsafe firearm and may cause injury or death.

Modifications to a firearm may result in personal injury or death, cause the firearm to not function properly, or malfunction, and cause the firearm to become unsafe.

Installing choke tubes on a TAC-14

This is a task that most local gunsmiths should be able to do for you.  You just need a lathe, reamer and tap.  The barrel should be assessed for compatibility with choke tube systems, basically, it needs to be thick enough and can’t be chrome lined if you are running high-speed steel cutters like the ones from Manson Precision shown here.  For a more detailed explanation of the choke installation process, please see this link.

I chuck the barrel up in the lathe.  There are a number of different ways you can set this up, but for a short barrel I plan on refinishing, this works fine.  I wrap some painters tape on the tube and use a dial indicator to ensure it is concentric to the bore.

I cut the recess for the REMchoke system using a reamer that is guided by a bronze pilot.  The pilots are sized in .001″ increments from .725″ to .729″.  The pilot should pass through the bore with a light drag so the tool is centered.  The reamer is held in the lathe’s quill chuck.

The reamer is coated in Do-Drill cutting oil and fed slowly into the barrel.   I use a spindle speed of 70 RPM and take my time.  I stop the lathe, clean and lubricate the reamer often.  If you get too many chips in there you can either drag a chip on the finish surface and ruin it or potentially damage the reamer.

The reamer cuts down to the muzzle.  The final part of the reamer makes sure the muzzle is perpendicular to the barrel’s bore.

The barrel is removed and cleaned with compressed air.  The barrel now needs to be threaded for choke tubes.  A choke tap is used for this.  This is a large tap that is guided by a bronze bushing, similar to the reamer.

The tap is turned in with a large tap handle.  It is coated in Do-Drill cutting oil.  Unlike traditional taps that are often backed off to break the chip, the manufacturer of this tap recommends turning this tap all the way into the bottom of the cut before backing it off.

Removing magazine dimples from an 870 TAC-14

Perhaps the biggest advantage of the Mossberg 590 Shockwave over the Remington 870 TAC-14 is the ability of the Mossberg to accept one more round in its magazine.  The TAC-14 magazine tube is threaded the same as any other 870, so aftermarket extensions will fit.   However, like Remington Express series shotguns, the magazine cap on the TAC-14 is secured via a plastic plunger inside the magazine tube.  This plunger is held in the tube via a pair of crimped dimples that prevent a traditional follower or shell from passing through, prohibiting the use of magazine extensions.

These dimples can be removed by either hammering of cutting them out.  I’ll do a brief overview of each method.

Removing magazine dimples using the socket method

Removal of 870 magazine dimples with the socket method is fairly straight forward.  You simply need a hammer, punch, deep well socket and vise.

Start by finding a deep well socket that fits snugly into the magazine tube.

Next, secure the socket in a vise.  The socket now acts as a mandrel that you can reform the magazine dimple with. You can use a small hammer or a punch (as shown above).  You need to be careful not to damage the magazine tube when performing this.  The tube is soldered into the receiver and can’t be replaced without an expensive trip back to the factory.  I’ve used this technique over the years, but now prefer to simply cut out the dimples, as shown below.

Cutting/Drilling out Remington 870 magazine dimples

My current preferred method to remove the magazine dimples from an 870 is too simply cut them out.  This could be as simple as using a drill bit large enough to remove the dimple and deburring the inside of the tube.  I prefer to machine them out with a 3/16 solid carbide end mill.

I simply secure the magazine tube in the milling machine vise and use the end mill to cut out the dimple.

When completed the cut looks like an oval.  It is important to note that this cut is hidden under the barrel’s lug, so you can’t see it.  The downside to this method is water or dirt could work its way into the magazine assembly, whereas with the “socket method” this would be less likely to happen since you didn’t cut two new holes into the magazine tube.

Ghost ring sight installation

I’ve found the addition of ghost rings sights to be exceptionally helpful on the TAC-14.  I decided to install a set of Wilson Combat/Scattergun Technologies Trak-Lock II sights on this gun.

I like to begin with the rear sight installation.  I mount the receiver in the milling machine and locate the two holes with a spotting drill.  The rear hole is located on a radius, if you don’t spot the holes the drill will most likely walk and you’ll have a problem.

I run a tap in a guide after the tap holes are drilled.  Again, careful on the rear hole, you don’t want the tap running in crooked.

Time to move on to the front sight.  I use a belt grinder to remove the front sight bead.

This picture is a little out of order, since I don’t install the front sight until after the Cerakote is applied, however, I felt this was the best place to put it in the post.  The front sight simply epoxies on over the bead base on the front of the barrel.  I use blue painters tape to help protect the finish and control squeeze out. Additionally, the front sight can be cross pinned with a 1/16″ roll pin through the sight and bead base.

Cerakoting the TAC-14

To begin the Cerakote process I degrease all the parts.  In this case I am soaking both the TAC-14 and a Mossberg Shockwave in a tank of acetone.

The parts are heated in a Brownells curing oven to remove any remaining solvent or oil.

The parts are placed in the blast cabinet and blasted with aluminum oxide media.

A really clean looking part comes out of the blast cabinet.

Finally the parts are hung and cerakoted.  In this case I am using Cerakote Elite in Concrete color.

During the reassembly process I installed a Wilson/Scattergun Technologies oversized safety (above, right).  It has a larger head than the factory (above, left).  I find them easier to operate.

After final assembly, here is the finished gun!

Looks great, doesn’t it???

To buy or customize your Remington Tac-14 visit Brownells!

To learn more about the Tac-14 see:

Review: Mossberg 590 Shockwave vs. the Remington Model 870 TAC-14

SHOCKING SHOCKWAVES: Rem TAC-14 v. Mossberg 590 SHOCKWAVE review, part 2

Shotgun Duckbill Review: Paradigm’s GATOR