Nothing against anything your saying, but a lot of the information is somewhat subjective, and lacks a lot of relevance. Your comparing their loads that they were comfortable listing in a public magazine, against your (I am assuming, correct me if I am wrong please) hand loads that you worked up to likely near maximum safe/accurate loads in your particular rifle, just like the rest of us do. Neither of these loads are pressure tested, or even worked up to the same initial signs of over-pressure (then backed off) such as ejector mark, increased bolt lift, etc., to compare apples to apples, so for instance, you may be running 68,000 psi, and their loads may be at 63,000 psi, or they may be able to add 2 grains before they get an ejector mark, and you may be .5 grain away from the same pressure sign, or vice-versa, who knows?
Not saying anything against the wby, nosler, or anything else, just that this is a somewhat arbitrary comparison, and should be taken with a grain of salt. I do however believe that there absolutely is a point of diminishing returns, for instance I am running a 156 out of a .264 win mag at 3200-3225 range before I find any pressure signs, and around 3175 fps consistently with no signs or wear on the brass. The real world numbers I see from 26 noslers and 6.5-300 wby's that are worked up to pressure then backed down for a safety margin are not very impressive in comparison when considering they are using nearly 20 grains more powder at times, and may get 50-100 fps more generally on the loads they end up sticking with. But when I compare, I compare my results, which won't be found in any reloading manual or magazine, to others people's actual results as well, where they began to see pressure signs, and so on.
In other words, I have no doubt that a 27 nosler will outrun a 270 wby when a fair comparison is drawn up, but it is encroaching on a point of diminishing returns, and the cost of shortened barrel life, extra cost of powder, and so on, may be more than some want to pay. The same could be said about nearly any other overbore cartridge vs the next larger overbore cartridge.
