Sabrina exhibited a rather large change in zero when you change from the Black Hills 69gr SMK it was zeroed with and PMC 55gr FMJ.
When I expressed this change in a conversation with Erin and a couple of her minions on Facebook, someone with more know-how than me expressed disbelief that it was as large as I remembered it.
I vowed to get back to the range and confirm it.
Because Black Hills 69gr SMK has the same zero as M855, I'd intended to do the confirmation with the much cheaper and much more available round.
Just in time for all the local ranges to make M855 forbidden.
When I fell back and punted, I couldn't get any new 69gr SMK...
Now I'm in no-contact exile.
But I swear I'm going to get right on it!