Sounds like you got few things going on. I am not a 277 caliber fan, not that it does not work but for me and my opinion, not a fan. I am fan of 284 so if it were me, I would change the 270 it to a 280 or how about a 338/06!
I am a firm believer in a miss is a miss horsepower included. A 416 is no more deadly than a 243 if the shot misses. Any one who says horsepower makes up for shot placement has not tipped over many game animals, its all about shot placement with a quality bullet. A 1200 pound bullwinkle will take just as many steps or drop in its tracks from my 340wby has they have from 7.08rem. Every animal and every shot has a set of different rules. The animal and shot cannot be predicted.
I have experienced, a light weight, lighter the better rifle can be carried and shot more accurately than a heavy rifle in what most would consider under horsepower cartridges. The name on the head stamp as little to do with felling game, its all about placing a quality bullet in the engine room, nothing more, other than being able to tote a rifle for days in the hills which means also shot placement.
Family and friends use a 22.250 and bring home Alaska meat every year.
I would build the lightest rifle I can in a caliber that I like or prefer.
good luck