That's quite an "opposite end of the spectrum" approach.
The thing that makes a 6BR not so ideal for a deer rifle is the fact that it doesn't feed well in repeaters. Some guys have done a lot of tweaking to their magazines and manage to get them to feed, but generally the short stubby case is hard to make feed reliably. Performance wise it's adequate but not overly a powerhouse, it's essentially a short .243 that will do 98% of what a .243 will with 30% less powder. I'm not a big fan of small calibers for deer but with good bullets it would work, still the feeding issue would rule it out for a deer rifle for me.
The 26 nosler is certainly a capable deer round, overkill to some. It wouldn't be my first pick mainly because I'm kind of getting away from magnums into the milder kicking rounds that I find easier and more fun to shoot. That doesn't mean there's anything wrong with a 26 nosler for deer though, I just don't want to carry the heavier rifles with 26" barrels that you'd expect for that round any more. My latest deer rifle build is a 6.5x47 Lapua with a 22" barrel that I'm finding to be a really sweet shooting deer round.
