The core-lokt isnt a bullet that i would be sighting in at 300yards IMO. It performs its magic at closer distance's normally. For long range look at the ballistic silvertip or the accubonds....something along them lines!! Good luck!
If you want I can run that through my balistics calculator? When you say sight in for 300yds, you want it to hit at zero there? I suspect the MRT will be fairly high like that. I like to zero hunting rifles with MPBR at a 6" target. Then the farthest the bullet will rise above line of sight is 3" and you'll have a MPBR where the bullet falls 3" below lone of sight.
If you want to properly preserve velvet antlers, you will have to inject & brush them with formaldehyde or some of the new less toxic chemicals (4 in 1 solution works great as does Knobloch's antler in velvet tan) as its easier to use however, both will work.
First, using rubber gloves take a razor blade and make small incisions at the tips of all points about 1/8". Next hang the antlers upside down, allowing the blood to drain. Starting at the bases inject the solution into the...