Ok, back to the 7s and ideal guns for them. Single shot rifles (Break action rifles) seem to be made for the flat shooting 7mms like 7 x65R, 280 Rem and 7RM. Both the 7x65R and the 7RM are the most sold calibres on this kind of rifle. They are mostly used in rough terrain like the Alpes, Scottish highlands and so on, everywhere where weight counts. Should be also perfect for the Rockies I suggest. They are light (5 6.5 lbs.), short (1m) and responsive. They deliver excellent handling characteristics and superb precision out of the box. Barrel length between 23.5 and 25,5 . Take them apart into 2 3 parts with the scope mounted or not and bear altogether in the backpack. Longest part will be the barrel. If more calibres are requested all someone has to do is to order an extra-barrelled action, done. These rifles are made for hunting goat, sheep but also deer on all responsible distances.
Calibres from 222 338WM. For real artillery from about 30 R Blaser up to the 338s this type of rifle is too light, even braked (IMO).