Finally went ahead and had one made this past summer, and put it on a Savage Axxis 2 action. Liked it so much, I ordered another barrel from Douglas. Predator contour with a one in 7 twist, on both. 20 inch barrels. I wish I'd have made one of these over 40 years ago, and if so I'd have a lot less 223 varmint rifles.
This past season dropped a 175 to 180 pound Blacktail at 50 or so yards. Front chest shot, took out the top right ventricle.
Drop dead at the shot. Nosler 95 grain Ballistic Tip, fueled either with 24 grains of either H 322 or Benchmark, had both loaded up but don't remember which one I grabbed. Still did the job, with no fuss..
Before season was ringing steel with it at 300 and 400 yds with NO problems, with 75 grain to 105, and 108 grain bullets.
Between the 6 x 45 and the 6.5 Grendel on a Ruger Predator Action, at an older age I think I have whatever I need to drop my annual deer.
Low recoil, pretty darn accurate, and set up to shoot 55 to 115 grain bullets out to 300 & 400 yds accurately. It will run 100 grain bullets with an MV of 2600 fps and 105 grainers at 2550 fps.
75 grain HPs in it will blow sage rats into red mist better than 22 caliber bullets out of a 223 with a 40 to 55 gr bullet...
Nothing "NOT to like" about the 6 x 45. The military should have used it instead of the 223 in Vietnam.
As CKat posted, it definitely kills above its weight class....
