The chamber reamer was cut by (PTG) Pacific Tool & Gauge.
I beleive the 416 Barnes isn't has popular as some of the others is because of lack of good bullet selection in the 416 caliber.
The 416 caliber really lags behind in bullets that will work well in a tube magazine, however they are out there and I believe their sectional density will offer better penetration.
A benefit of this round is that it is based off easy to get 45 70 brass.
Next I need to get some dies made.

David