Question fro Mr. Randall Rausch

[Marc]

Sir,

I am building a new Stainless Steel 12,5" barrel from a Delcour (Belgian barrel maker) barrel blank.

1/9" twist. 5,56 Target chamber (JGS reamers). Barrel diameter at the fsb. 0.750".

I will only use 5,56 NATO pressure ammunitions.

I would like to know Which gas port diameter you will recommend for that particular configuration?

Many thanks.

Marc.
Belgium.