Got this as shooting ammo a few days ago. I thought the 3-place FC + 17 headstamp looked different, so I thought it was worth a post. Sorry about the crappy h/s pic; you just need to squint a bit.
Jon, you mean 17 not 77 do you?
10-4, Good buddy! Nice catch.
What is the product # on the box?
Other than the lot number shown, there is “XM855I” on the end flaps.