Here's my view on shotguns:
Now personally I feel that the range, power and one shot ability of a shotgun is where it needs to be, it makes for a more aggressive game play. However what I don't like is how someone with a shotgun can just ran straight at you taking bullets in the face and yet still get their shot off.
Personally I feel if your running around with a shotgun and get the trigger off first then you deserve the kill but if you run straight at someone whilst they are shooting you clean in the face then there is issues.
I feel there should be some kind of increased impact effect when holding a shotgun, for example if someone is running at me in a straight line and I'm loading a full auto sidearm into them, their accuracy should massively fall off making it harder for them to hit you. However as I've said if they get the jump on you then fair play, but for arguments sake if a guardian is static and a shot-gunner is running at them, then the shotgun shouldn't be so accurate whilst being shot at.
Similar to the argument against snipers, if your hitting them in the head then they should be put off their shot. If that makes sense, can't think of the terminology and words to explain it better.
Before its said, YES i know using a shotgun to counter etc etc etc but I prefer running a sidearm or a scout so for arguments sake, if your running at someone with a shotgun their shots should have an effect on your accuracy.
You’re talking about flinch, and snipers have it already, a shotgun requires no aiming skill, so a flinch on it would do nothing, the best way to do what you are asking is to decrease the speed you can draw a shotgun to a firing position from sprinting or sliding while being shot. Although i must say that nerfing shotguns in this way doesn’t make logical sense as it would make them useful only as a corner clearing gun and make it’s pve utility a lot less.
In my opinion, sidearms and submachineguns should be the de-facto counter for shotgunners, they should be buffed to counter sprinting shotgunners, but it’s a delicate balance.