In my novella, the main character is shot directly below the left clavicle by a sniper rifle. The bullet misses the bone, but would it have hit the subclavian artery or another artery? And if so, how long would it take for her to bleed out? She receives medical help from an off-duty paramedic within three to five minutes. Thanks!
I reviewed a couple of anatomy pictures and the subclavian artery appears to sit higher and slightly above the clavicle or collar bone. When looking at anatomy photos, red indicates arteries (as they are taking oxygen rich blood away from your heart to the rest of your body) and blue indicates veins (bringing oxygen poor blood to your heart and lungs for more oxygen).
That being said, the left chest has all sorts of major veins and arteries. A bullet can always miss these structures— we all hear those rare stories, but I generally encourage authors to stick to the right chest for a more believable scenario if they want the character to live. Ultimately, it is your choice.
The subclavian vein, which is nestled under the artery, could definitely be nicked or severed by a gunshot wound to this area (either the right or left side). Central lines are often placed to the subclavian vein which is accessed just benenath the collar bone.
If the bullet hits the subclavian artery, the character would bleed out fairly immediately— in roughly under two minutes without any medical intervention. Your paramedic arriving in three to five minutes would likely be too late. Direct pressure to the area will help. It is hard to stem bleeding from an artery this size, but pressure could help delay the onset of death for another few minutes.
If the bullet hits the subclavian vein, the bleeding will still be brisk but could be more easily controlled with pressure than bleeding from an artery.
If you want an injury that will bleed, but would likely be survivable, I would pick the subclavian vein with people at the scene immediately applying direct pressure to the gunshot wound.
Hope this helps and best of luck with your story!