I say go with your friends. Enjoy some good company. Keep the shoulder immobile, do not use that arm at all. If you can shoot a .22 from a bench or something without upsetting the shoulder then go for it. If not just go and hang out with your friends.
I am 35 and my shoulder hurts like the dickens when it gets cold, and after some physical activities. I ignored the doctor's warnings after dislocating my left shoulder. I rode 3 motor cross races, and played in a football game. It hurt like no tomorrow after each time. It hurts today as well. If it would have been hunting season I most likely would have gone hunting as well, and I am a lefty shooter.
The thing is I wised up. I listened to a trainer, and physical therapist and did strength training as was suggested by the doctor. I missed a season of wrestling, and was told by the shidoshi of the dojo if I tried to work out he would kick my tail with a steel toed boot. I now only wish I had listened sooner.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.