My stalking rifle is a 6.5x47 Lapua custom lightweight build on a SST Rem Model 7 with 20" fluted 1 in 8 twist Kreiger. Rifle is in a McMillan Hunters edge stock, topped with a B square rail, Nightforce alloy rings and Nightforce 2.5 - 10 compact and Jewel trigger. All up weight 6.5 pounds, it shoots under half MOA and has proved more than adequate on red and fallow out to 400m so far, frankly haven't had any need to test it at further range. I note that you seem to be looking at light bullets, which I think is a mistake, might as well stick with the 243 if you go that way, you'll loose all the advantage of being able to use the heavier more efficient pills like the 123 & 140 grain Amax, which have proved to be excellent killers and superbly accurate at all ranges tested so far on deer (and anything else that needed to be despatched).
In the 20" inch barrel, with non brass wrecking loads, V runs at 2750 for the 123 and 2650 for the 140, trajectory allows you to aim straight at anything between 0 and 250m and still be within 2.5" rise or fall. With the NF mildot reticle this is a bullet flight path of just under the first mildot above X hairs @ 100yds, just above the X hair at 200, just above the first mildot under the X hair at 300.
You could also re barrel your Tikka with a 1 in 8 twist 24" and long throat it so you can seat a 105 grn Amax (or other suitable LD pill) with the start of the boat tail at the base of the neck about 2.85 - 2.95" OA, which allows for a full case of ADI 2217, and get 3100 + fps (243 AI improved performance without the AI chambering), provided the mag well length on the Tikka allows for the longer overall cartridge. This works superbly in my custom Weatherby MkV lightweight (which has a long enough mag well) and gives slightly better terminal ballistics to the 6.5x47 with any bullet in a lightweight stalker, and an even flatter trajectory. This setup lets you get the best out of your handloads and you can use any factory ammo if you need to. Note, in my experience a standard Rem short action mag well is NOT long enough to allow reliable feeding for this 243 load setup when cartridge OA length exceeds 2.8"
