.270
Really depends on the load, but the .270 is typically the more powerful of the two.
90% of 270= 90% * 270= 0.9 * 270= 243
General rule of thumb is that the best caliber is the one which best suits you. Of the two, .270 would be the more powerful round. Both are substantial for hunting something like deer, although the .243 is probably better suited for the experienced hunter, whereas the .270 would be a little more forgiving to the novice hunter. The .270 is a necked down .30-06, and the .243 is a necked down .308.
270
30-06 is more powerful
If 7mm Magnum, it trumps the others.
.270 is the larger calibre of the two.
The parent case of the .270 is the .30-06, necked down. The parent case of the .243 is the .308 Winchester, necked down. Aside from the larger diameter of the .270, the .270 has a longer case.
The .243. It's basically a necked down .308 Winchester.
10 percent off is 90% of 270 dollars 270 x 0.9 = 243 270 - 10% is $243.00
As a fraction 9/10
Model dependent