Magpul D60 giving me issues

I bought a mag pool D60 and it has been giving me nothing but issues when trying to load.

I am trying to load with 300AAC which I could have potential feed issues when firing but loading should be the same right? I have watched several videos and couldn’t load more than 10 so I unloaded it and ended up getting about 35 in before it started giving me issues where the last 3-5 round won’t seat properly.

Any advice???