That's the million dollar question on the table.
Ideally, the 147 ELD-M with its higher G1 BC of .697 vs the 140 ELD-M's G1 BC of .646 would mean that the 147's would perform better in the wind - meaning that the 147 would require less horizontal correction than the 140 in the exact same wind. The challenge we are facing is that the 147 is (obviously) heavier than the 140, and therefore would travel slower with the same powder charge than the 140, and slower speeds mean that the gains from the higher BC may be lost due to a slower round.
At least from what limited work I did the other day in JBM, it appears that at least in my gun the 147 should show a small improvement over the 140, IF the 147 is going at or faster than 2800 fps, it will need 0.1 less elevation to reach 1,000 yards, and it will need 0.1 MIL less wind correction in a 5 mph full-value crosswind at 1K than the 140 I'm currently using in my 6.5 Creedmore bolt gun.
0.1 doesn't sound like a lot of advantage, but in this game on the paper targets we (NorCal) shoots at 1K, that can mean the difference between a 9 and an X, or a complete miss and a 6. Those add up. Points matter.
Guys, if I've missed anything, jump on in.