For bulk instagram downloading use this app.. works great. You might get 503 error every now and then but ig you keep trying and it will eventually work.
You will need python installed first. Then you can use the app to download whole profile.
But there is 2 issues:
1. IF you download someone profile as a guest then this script will only be able to download lower resolution version of pics.
2. And if you supply a username/pwd to login then Instagram will probably ban your account because they don't like people downloaing content.