For your .243 Winchester, the following are MAX loads:
85 grain Sierra BTHP, 42.0 grains of W760 Overall length should be around 2.690".
55 grain Nosler ballistic tip, 50.0 of W760, set overall length of this cartridge at a short 2.600". (Seat the bullet deep).
I would recommend sticking with the 85 grain Sierra bullet, and start around 40 grains and work up to the 42 grain charge. This should be an excellent load. Use CCI or Federal primers.
For your .270 Winchester:
130 grain bullet, (I use the Sierra Gameking)
54.0 grains of W760 should be good for about 3000 fps. 54.0 grains is MAX, so don't exceed. I think the 270 is at its best with the 130 grain bullets, so I wouldn't deviate from that weight. Use CCI or Federal primers. My preference for both calibers is the CCI 200 standard primer.
Both the 85 grain .243 load and the 130 grain 270 load should be excellent all around performers. The .243 can be used effectively for deer sized game with the 85 grain Sierra, and it works very well on varmints of course. The 270 load should be quite accurate, (around 1 to 1 1/4 MOA) and more than powerful enough for game up to and including elk.
Good luck.
green 788