So this looks to me, is typical first firing with alpha ocd brass signs at the case head. The web is so strong on these cases it doesn't expand much first pop causing it to not grip chamber well, this slams the case head back to the bolt face, giving you that ejector cut signature.
My origin does same thing to primers, cratering at medium to Lower psi(probably gonna get it bushed eventually) those primers look very round at edges, I'd say your load it totally safe and what you're seeing is common with ocd brass upon virgin loadings.
I have not tried varget in the 6gt, only H4350, RL16 and IMR4166. H4350 has done great with 108-115gr bullets as well as rl16. 4166 gets a lil spicy above 2950fps, as will varget likely, unless you have a very long barrel.