C-fbmi, now you have my interest. I figured if anyone had tried something like this it would be you.
I no doubt chronographed it back when, but after 2 moves, I no longer have the data.......sorry. I just started with top end 7mm RM data and worked up with the slower powders. Seems to me I ended up about 3200 fps with 160 gr Parts. Volumetric comparison put it at exactly the same case capacity as a 7mmX300 WM which I also had at the time. Given the difficulty and cost of obtaining the 8X68 brass I did a bunch more work and some hunting with the 7mmX300WM. I also was working with a 7mmX300 Wby at the same time on a Ruger #1 with a 28" barrel. Did quite a bit of hunting with this rifle, took moose, caribou and sheep with it........very devastating cartridge with 150 and 160 gn bullets..........This was before the STW hit the scene.
If you have or can lay your hands on an adequate supply of RWS 8X68 brass I highly recommend this cartridge. It is close enough to work with a magnum bolt face and it feeds like butter and works through any action that will take a 300 WM. It is kinda like a slightly skinnier version of the 28 Nosler at about the same brass cost.......but will feed flawlessly from any donor action based on a belted mag with no feed rail work at all......I have my doubts about the 28 Nosler.
I thought briefly about a 28 Nosler but I have a 7mm RUM so I could not justify it under any realm of reason.........I also have 1 or 2 7mm RM, a 7mm Wby, a 280, a 7X64, a 7X57 and a 7-08.........just no ballistic holes left in my 7mm line up and I refuse to pay the price for Nosler brass !!!!
This all came about because I was working on a whole line up of magnum hunting cartridges using beltless cases. The first was the 7X68 Imp, but was also going to go down to 6.5 and 25 later. Next was a 30 and 8mm on the same case then up to 9.3, 375 and 416 on a shortened 404 case very much like the Dakota or Nosler case and then up to a 458 and 475 on a shortened Rigby case to cover all of the worlds game with a series of beltless magnums. I started with the 7X68 Imp reamer as well as the 475 reamer and decided to use the 7X68 reamer for the 9.3 as well, given the case capacity and what I know now about the 9.3X300 WM.
As I said I'm working on the 8mm version and have a 475 barrel and reamer for the 475 version which I will build one day and I think probably a 9.3X68 imp is in the cards one day as well but likely not the rest as there are so many cartridges available now that these would only be expensive redundancy.
