Well, if I don't die laughing first, I will help you.
Everybody thinks their 6mm is faster than the 240 Wby, but you never see them post up anything that they kill with it. There is one guy up in Montana that actually has managed to kill something with a 6-284 past 1K and that is all.
So to build a 240Wby that will max out, get your smith to use a minimum SAAMI reamer and then throat it to the 105-115 grain VLDs. Leave the small bullets to the people who want to get close and powder burn their deer.
Load the case up with a shovel or so more RL22 than 50 grains and hammer in some Fed 210 GMs. Jam the bullet in the lands, close your eyes and pull the trigger. If you still have all of your fingers then grab the hammer and open the bolt and put in another one except this time keep your eyes open when you shoot.
With a 28 inch barrel you should be able to get about 3200+fps with a 115 Berger and a little less with a SMK.
Do not shoot the gun on hot days!
The barrel on my rifle is a 6 groove 1-8 twist 30 inches by Clay Spencer. I get a speed of about 3250-3275 fps. It must be very smooth inside because a lot of people claim they cannot get the speed I do with the Bergers because their barrel tears them up. Some gunsmiths will advise a 1-9 or 1-10 twist inorder to prevent bullet blowup at high speed. Secondly, Clay builds a chamber so tight and true that you can really get some good speed out of it. When he trues up an action it is good and true.
I get one or two firings with my brass and every once in a while I will get three if I tape the primer in.
Considering that a hunting trip cost me $2000 to $3000 dollars I really don't care about a few pieces of ruined brass. Of course to protect the throat I do not shoot the gun except every once in a while and then I am careful to keep it cool.
With the 115 Berger I have shot through antelope at all ranges from 150 yards to 1140. It always exits with about a four inch hole no matter what distance. At 800 yards it broke the near shoulder, then a rib and then got another rib and then broke the far shoulder and exited on a buck antelope. At 550 yards, I shot through a large boar hog DRT and then into the sow behind him and it went through her pelvis and exited.
So, I would have no hesitation to shoot at an eastern whitetail buck out to about 1400 yards if I had a calm day. Naturally, I am one of the hated infidels who will actually back up in order to make the shot interesting. Just killing an animal to see blood on the ground does not do much for me.
Just one more piece of advice. Get a nice 260 or 308 and use it to practice. That protects your 240 for the serious business and it is harder to kill something at 800 yards than most people realize so practice is important.