Well, that all makes sense, but it is possible to load put to that length, but it have to be single fed. And at the length you are now, it sounds like it should fit into any action, and magazine . The rem is longer, and the Winchester usable mag space is about 3.630+-.
As to the performance with your bullet, the 40 yard shot results are completely understandable, and the results at the longer range shot sounds good. I have some of those, that I had originally intended to shoot in my Sako 75' in STW. It tolerated them, but couldn't get them to shoot uniformly. My seven mag 700LSS loves them. I am building a 280 as we speak, and may try them in that. Your velocity and accuracy seems very good, so, if it aint broke, don't fix it. Good luck with your unpacking, and setting up everything. Maybe your new set up will let you organize a little better.