100% a mag issue. Fix or replace the mag and ensure the bullet tip is angled up towards the feed ramp and it should feed the cartridge without issue. I generally tweak mags a little to ensure this is happening.
You can see the one Sid feed lip has been bent up a tiny bit, you can always "tune" metal mags with the correct tools. The one feed lip needs to be slightly bent down so it contacts better. There are a few videos out there on how to do this.
The only time I've had a bullet nose dive was my 6xc MPA chassis Stiller SA criterion barrel with any mag except a AI brand mag. Magpul and Accumags nose dived. same as yours.I have just put together a 7 mm PRC build. Proof Reserach Barrel, Lone Peak Fuzion Ti action. Hawkins Hunter Bottome Metal, with the Long Action Magazine. Trigger Tech Trigger. Pure Precision Stock.
Problem: When there is only one bullet in the mag, it almost always jams with the bullet tip going downwards. If the mag has 3 bullets in it, the first 2 feed smoothly. There is a lot of play where the magazine can be jiggled quite a bit while it is in the bottom metal. If I hold the magazine up from the bottom, the single round will feed. Put washers between the bottom metal and stock, and it didn't make any difference. I have attached some photo's and video. I would welcome any suggestions.
Hawkins answered your issues on this thread.Thank you all very much!!!! I will be calling Hawkins.