Porting a shotgun barrel with a drill

Porting a shotgun helps decrease muzzle rise and felt recoil.  I decided to port the 18.5″ barrel on my 870 Remington shotgun.  This is a quick and easy project that requires minimum tooling.

I ordered the following items from Brownells:

  1. Barrel porting fixture (952-100-001)
  2. Do-Drill cutting oil (083-007-016)
  3. Graphite Black Cerakote (100-003-743)

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The porting kit includes a set of vise blocks to secure the barrel, an aluminum drilling fixture, a hardened drill guide and a drill bit.  To port your own barrel, you just need to supply the drill.

porting jig

The kit we used (kit #1) has a drilling fixture with 35 holes on each side.  The supplied bushing guides a #40 drill bit (.098″).  A 23 hole per side kit (kit #2) is also available, this uses a #31 drill bit (.120″).

Before you begin, I would highly suggest stocking up on a supply of drill bits to replace the bits you may dull or break.

The barrel is secured in the vise using the plastic jaws provided in the kit.

The barrel is secured in the vise using the plastic jaws provided in the kit.

I used tape to mark the beginning and end of where I wanted the ports.

I used tape to mark the beginning and end of where I wanted the ports.

The drilling guide is secured to the barrel using clamps.  I used blue tape to mark where I wanted to drill the holes.

The drilling guide is secured to the barrel using clamps. I used blue tape to mark where I wanted to drill the holes.

A dowel is inserted into the shotgun's bore to protect it during the drilling process.  The drill hits the wood, instead of the inside of the bore when it breaks through.

A dowel is inserted into the shotgun’s bore to protect it during the drilling process. The drill hits the wood, instead of the inside of the bore when it breaks through.

A hardened steel insert is used to guide the drill bit.

A hardened steel insert is used to guide the drill bit.

The drill is coated in Do-Drill cutting oil.

The drill is coated in Do-Drill cutting oil.

And the hole is drilled.  The process is repeated until all holes are drilled.

And the hole is drilled. The process is repeated until all holes are drilled.

Finished ports.  There are slight burrs on the inside and outside of the barrel.  I used a flexhone to remove the interior ones and abrasive cloth to remove the exterior burrs.

Finished ports. There are slight burrs on the inside and outside of the barrel. I used a flex hone to remove the interior ones and abrasive cloth to remove the exterior burrs.

Ported Remington 870 barrel coated in Graphite Black Cerakote.

Ported Remington 870 barrel coated in Graphite Black Cerakote.

For more on shotgun porting read Porting a shotgun barrel on milling machine