Thanks, I have read about 10 of 100+ pages.
Somewhere in there I found an explanation of Absolute Hammers by Steve.
Now I have my head around this that the ogive is marginally smaller diameter than the bore with a slight concave ring around the diameter behind the Ogive before meeting the bullet diameter of the shank this produces less drag resulting in higher velocities than similar weighted Hammer Hunter projectiles and others .
Of all the stuff I have read, all of the questions I have asked
I didn't really find anything showing or describing the difference in the Hammer types or the reason they perform so differently in the same weight.
I think I'm getting the gist of it now.
Now to connect with our Aussie contact and import some to the mainland..