Are these basiclly the 'hawk' calibers? If not, why haven't we been seeing more of these? capt david

I believe all the Hawks are based on improved 06 cases now. The Howell line from American Hunting Rifle is another of the same type. Take an 06 reduce the taper and move the shoulder forward. Not much different that the Gibbs.

The Hawk line started out with a 375 Whelen improved which was then "improved with a 9.3x62 reamer". Dave Scovill changed the base to use cheaper '06 brass. It is not a Gibb's knock off.

The Hawks look great and work well.

Regarding why we don't see more x62 'cats, take a look at the dims of the '06 next to the 9.3x62. There just isn't enough difference to make a hill of beans. When you can blow out an '06 case that you bought for a song here's not much reason to use the other.

While the Hawk is not a Gibbs knock off it is close. The 9.3X06 had the taper reduced and the shoulder moved forward. The Hawks has a little less shoulder angle. I measured the water capacity of a 338Gibbs and the 338 Hawk and the 340 Howell. The capacity of the Gibbs was about 2grs more water than the Hawk and the Howell was 2 grs above the Gibbs. However if you reduced the case length of the Howell to the same length as the Gibbs the capacity was a tie. So I would say if you were forced to keep the COL the same in both the Gibbs and Howell the net capacity would be the same.

Loaded to the same pressures I doubt you would see any real difference.