I'm not sure trust is the right word for this . I would trust them all if it's the only one I had .
Are you asking only caliber or the bullet/load of any catridge ?
I do see what your saying about how this could get interesting . For me and if I had a choice . I would not want any of the big calibers 50 , 338 , win mag , ultra mag . To big , to loud , to much recoil . I may not even want any long guns for SD . Maybe just a good pistol that can hold 13 or more rounds .
Why do I carry a 45 ? because they don't make a 46