What do you guys use as a gun holder when backing in my pack doesnt have anything built into it so i wanted to make something that will hold my muzzle loader when packing in?
A lot of guys here use the Kifaru Gunbearer, which I also own. I also recently purchased the Crooked Horn Gun Commander.
The Kifaru Gunbearer rides under your armpit and doesn't require a sling. The weight is mostly transferred to the hip belt on your pack.
The Crooked Horn Gun Commander requires a sling and holds the rifle on your shoulder with an attachment on your pack's hipbelt, which provides a second point of contact to keep the rifle from sliding off your shoulder. The bulk of the weight is borne by your shoulder.
Each has its pros and cons, but both methods allow you to walk hands-free and carry your rifle while still wearing a pack.
Kifaru gun bearer....if you want something to attach it to your back (not quickly accessible) I'd get some 1/2" or 3/4" buckles and make something that works for your pack.
I have a Stone Glacier weapons sling. Minimal and does the job. It attaches to carry your rifle on the side of your pack but can be released and ready to shoot quickly w/o taking off your pack.