My go-to (and currently my only) pack is a MR Metcalf. Love the pack. However, I find that if I have the pack on for an extended period of time, my right shoulder will get a little bit sore. For example, I put about 5.5 miles on yesterday morning here in the hills. I also carry my rifle on my right shoulder typically. To my knowledge, I have the pack adjusted properly, and my weight is centered and distributed properly. Could there be something I’m doing wrong to cause this? I certainly don’t think it to be an issue with the pack/frame design itself. Any insight would be appreciated.