It chrono'ed 3557 with my handloads which were more than a grain under max in at least one book. However, itwas 3 over in other books. The one that counts is the one by the bullet manufacturer I was using....NOSLER and it was a hair under w/140 gr and IMR 7828 from its 26" pipe it had an avg speed of 3557(ten shots) and on top of that it was a sub moa shooter
I use the loading manuals only as a guide and for a starting load.Just because the book lists a load does not mean that the particular load will be safe in my rifle,even if I use the exact same components as listed in the manual.I have seen pressure signs with some rifles using those same identical components and was still a few grains under the maximum load.On the other hand,I have had loads that produced nearly 200fps less than the manual velocity even with identical components and barrel length.In many cases,manuals produced by the powder companies,and even by other bullet manufacturers have been much closer to my rifles,than the manual from the manufacturer of the bullet that I was using.
As for the 7mmstw,I use it because I hunt elk and moose as well as deer,and on the larger game,the extra power is certainly welcome.If deer was my only big game,I would most likely use a .257" bullet as I consider even the .277" bullet overkill. As well,the extra velocity reduces wind drift which can be a factor even at 300 yards,let alone 500 yards.