Well the first time trying out the back pack with 40 pounds in it which included my 15 pound 6mm Norma BR. and my Browning BAR 30-06 in a soft case. Both rifles fit in the pack's scabbard. It is very comfortable and I walked down hill which is a 45 degree angle for a 1/4 mile and then back up the hill. I thought that I did very well for a guy that just turned 65 and am very out of shape. I have been walking for about a month now and have lost 16 pounds.
The only thing I may have to add to the pack is making the belt that goes from one shoulder strap to the other longer. I weigh 232 pounds now and have a large barrel chest. The waste strap is plenty long enough for the guys with big beer bellies.
The other thing I should mention is that the padding that goes all the way up your back is great.
I'll try to get someone to take pictures to post this weekend.