Yea, all of us can get to more than we can grip. For now, you could use a reverse grip like with deads and keep reversing it to hit the shoulders evenly, but you're still limited to your grip.
OTOH, traps respond to high reps pretty well (I'm sayin' up to like 20) for me, but even better down around the fives.
If you look around your gym, you may find something like a machine bench or press with rubber covered handles that will be at your sides when you stand between them. This is a great shrug position, pulling straight up the side of the legs. I've even kicked my shoes off to stand on a bench in my socks to use a machine. (to keep from ripping their upholstery) The foam or rubber grips will allow you to pull more weight, but not as much as straps.