129 SST vs 140 SST?

I'm working up loads for my 6.5x55 and would like to hear your experiences with the above bullets for whitetails. I'm getting sub 1 MOA groups with both. I'll be shooting from 50-600 yards this fall. What are your real world experiences with these two?

SST is a pretty fragile bullet, similar to the Nosler Ballistic Tips. I would use the 140's for a little more penetration and weight retention , especially if a close shot presents itself. Both are accurate and more than capable of taking deer , but I'd rather have all of the advantages the 140's have . Higher BC , sectional density and on game results.

Those were my thoughts, too. Thanks for confirming.

Another vote for the 140's