Installing Venom’s Antidote muzzle brake & tactical gas block on an AK (Kalashnikov) barrel- cut, crown and thread an AK barrel

Customized Arsenal AK
Customized Arsenal AK

Customized Arsenal AK

Installing Venom’s Antidote muzzle brake & tactical gas block on an AK (Kalashnikov) barrel

We decided to remove the standard gas block, front sight and brake from our AK rifle.  We wanted to install a Bolton gas block and the new, Venom Tactical Antidote muzzle brake, which required a 14x1mm left-hand thread on the end of the muzzle.

This project requires us to remove the barrel, strip the gas system and front sight assembly from it, install a Bolton gas block, cut, crown and thread the barrel, and blind pin and weld the muzzle device in place.

Prior to beginning our project, we ordered the following items from Brownells

We ordered the following from Venom Tactical

Our our project begins with a Saiga rifle converted to standard AK format by Arsenal.

Here is our base rifle before we start to work on it.  An Arsenal converted Saiga.

Here is our base rifle before we start to work on it. An Arsenal converted Saiga.

We verify the rifle is safe and empty prior to handling it.  This documents our work on our own rifle and is presented for informational purposes only.  The rifle is then completely stripped before heading over to the hydraulic press with our barrel press kit.

The barrel press kit. This includes the tools you need to remove and install the barrel. The two bars (bottom) are used to support the barrel or receiver when pressing, the aluminum block (left) is used to support the side of the receiver when working with the barrel pin, the barrel pin pusher (top right) is used to remove and replace the barrel pin.

The barrel press kit. This includes the tools you need to remove and install the barrel. The two bars (bottom) are used to support the barrel or receiver when pressing, the aluminum block (left) is used to support the side of the receiver when working with the barrel pin, the barrel pin pusher (top right) is used to remove and replace the barrel pin.

With the rifle fully disassembled, the barrel pin is pressed out of the trunnion using a hydraulic press.

With the rifle fully disassembled, the barrel pin is pressed out of the trunnion using a hydraulic press.

With the pin removed, this is the press configuration to remove the barrel.  Note the pressur is being applied to the field expedient lever that was constructed using scrap steel.

With the pin removed, this is the press configuration to remove the barrel. Note the pressure is being applied to the field expedient lever that was constructed using scrap steel.

The barrel is slowing removed the trunnion.

The barrel is removed from the trunnion.

Success, the barrel assembly has been removed.

Success, the barrel assembly has been removed.

The pins retaining the gas block and front sight assembly are soaked in Kroil.  A starter punch is then used to remove the pins.

The pins retaining the gas block and front sight assembly are soaked in Kroil. A starter punch, followed by a pin punch, are used to remove the pins.

The front sight pins were exceptionally difficult to remove.  Rather then waste time with a punch, a quick pass with the milled removed the bottom part of the assembly so what is left of the pins could easily be removed.

The front sight pins were exceptionally difficult to remove. Rather then waste time with a punch, a quick pass with the mill removed the bottom part of the assembly so what is left of the pins could easily be removed (right side of photo).

The front sight and gas block can now be pressed off the barrel.

The front sight and gas block can now be pressed off of the barrel.

 

The barrel is now stripped.  Work can proceed.

The barrel is now stripped. Work can proceed.

These are the notches left in the barrel after we pressed it off.  The gas block left similar notches.  The gas block notches will be covered with the Bolton gas block, these however, will not be covered.  We decided to Start our threads for the muzzle brake at the second notch and cut off the barrel at the first.  Since this will make the barrel less then 16", the brake must then be secured in accordance to ATF guidelines for a minimum length of at least 16".

These are the notches left in the barrel after we pressed the front sight off. The gas block left similar notches. The gas block notches will be covered with the Bolton gas block, these however, will not be covered. We decided to start our threads for the muzzle brake at the second notch and cut off the barrel at the first. Since this will make the barrel less then 16″, the brake must then be secured in accordance with BATF guidelines for a minimum length of at least 16″.

We use our hacksaw to cut the barrel to length.

We use our hacksaw to cut the barrel to length.

The saw marks are removed from the muzzle with a file.  Note: the notch on the right side is from a pin.

The saw marks are removed from the muzzle with a file. Note: the notch on the right side is from a pin.

We use the Manson crowning tool to recrown the barrel.  The Manson tool's carbide cutter will cut through the chrome lining of the barrel.  First, the 90 degree cutter is used, followed by the 11 degree.

We use the crowning tool to re-crown the barrel. The tool’s carbide cutter will cut through the chrome lining of the barrel. First, the 90 degree cutter is used, then it is followed by the 11 degree.

 

The finished crown.  Not too shabby.

The finished crown. Not too shabby- especially for an AK!

 

The outside diameter of the barrel is larger then the major diameter of our threads so it needs to be turning down.  The barrel is mounted into our lathe. with a three jaw chuck holding the chamber end of the barrel, and a crown saver equipped tail stock at the muzzle end.

The outside diameter of the barrel is larger then the major diameter of our threads; so, it needs to be turned down. The barrel is mounted into our Grizzly G4003G lathe. A three jaw chuck holds the chamber end of the barrel with a crown-saver equipped live-center at the muzzle end.

The end of the muzzle is turned down to the appropriate diameter, a few thousandths below 14mm.  Note the brass crown saved inserted into the muzzle to protect the crown.

The end of the muzzle is turned down to the appropriate diameter, a few thousandths below 14mm. Note the brass crown-saver inserted into the muzzle to protect the crown.

 

To ensure appropriate alignment, a thread guide (right) is used to align the tap (left).

To ensure alignment, a thread guide (right) is used to align the tap (left).

The barrel is secured in a vise.  The thread guide inserted into the muzzle.  This will ensure proper alignment of the die.

The barrel is secured in a vise. The thread guide inserted into the muzzle. This will ensure proper alignment of the die.

image_17

The 14x1mm left hand thread is cut.  The surfaces are lubricated with Do Drill cutting oil while the cut is made.

The 14x1mm left hand thread is cut. The surfaces are lubricated with Do Drill cutting oil while the cut is made.  Note: the threading guide has been removed in this pic for illustrative purposes.

The gas block is installed on the barrel with the Ultimak scout rail and lower handguard to verify alignment.

The gas block is installed on the barrel with the Ultimak scout rail and lower hand guard to verify alignment.

 

The gas block is torqued per manufacturers specifications.

The gas block is torqued per manufacturer’s specifications.

 

The muzzle brake is secured and stopped hole is drilled through the brake into the barrel.

The muzzle brake is secured and a blind hole is drilled through the brake into the barrel.

 

A steel pin is driven into the hole.  We hit it hard to make sure it is seated and verify that the brake cannot be removed.

A steel pin is driven into the hole. We hit it hard to make sure it is seated and verify that the brake cannot be removed.

A tig welder is used to weld over the pin.  We also welded the bottom circumference of the brake where it met the barrel (not shown).

A TIG welder is used to weld over the pin. We also welded the bottom circumference of the brake where it met the barrel (not shown).

 

The barrel assembly is pressed back into place.

The barrel assembly is pressed back into place.

The barrel pin is reinstalled.

The barrel pin is reinstalled.

Once the barrel is secured to the receiver, the entire assembly is degreased, blasted with aluminum oxide media, and coated in graphite black Cerakote.  The rifle is then reassembled. An overview of the process we use can be found here.

The finished front end of our rifle.

The finished front end of our rifle.

We are now ready to head to the range with our newly customized rifle.  A review of the Antidote muzzle brake will be posted as soon as we get a chance to put it through its paces.