Barrel porting has the advantage of the best suppression when used with an over-barrel suppressor, as the gas and noise is ported through the barrel straight into the suppressor ports. The disadvantage is that it will reduce all ammunition to sub-sonic velocity, even hypers.

Below is an example on an old slightly bent 10/22 barrel that I have had sitting around my workshop, that can't be used - but is ideal to show the process.

Stage One: Remove barrel from rifle

Stage Two: Center in lathe, align and remove sights.

Stage Three: Turn barrel as required, in this case to a parallel 16mm the whole length of barrel.

Photo to Right: Barrel has been turned and polished to a mirror finish.

Stage Four: Barrel is prepared for threading.

Stage Five: Porting design is calculated and drawn on barrel, in this case a spiral design

Stage Six: Barrel is ported by hand, and countersunk. As well as the spiral porting, I have made a 8 port muzzle-brake behind the thread.

Photo to Right: Barrel is cleaned and polished, both inside and out

Photo to Left: Barrel is sterilized in acid, then blued and polished.

Stage Seven: Custom suppression chambers and spacers are machined and anodized, including mounting kit to thread onto barrel, and reverse flow venturi unit for the end-cap

Stage Eight: Suppressor is assembled and ready to mount onto barrel.

Photo below: Barrel and suppressor are finished and ready to mount on rifle.