I'm running on the criteria of the OP and for long range heavy game like elk going from a 180 class bullet to a 215 is like shooting a whole different gun, I've rebarrelled a couple of 300 WSM's for guys who were running the 180 class bullets and I set them up for single sledding or in a Tikka with a 215 and both guys called me part way through the season and were just blown away by the upgrade going from a short throat with 180's to long throated for 215's, flat hammered some elk out in the 800 yard range. One of my favorite chamberings is that 300 WSM and 215, running mid 2900's with 24 inch but suppressed barrels.