Tim, I leaning that the bullet is a Paul Jones 335gr (4 Grease Groove) Creedmoor
Handi, does your bullet have 4 grease grooves and what does it weigh?
Do me a favor if you would and take the following measurements:
... Length of bullet
... Length from nose to leading edge of driving band
... Diameter of driving band
... Diameters of the grease groove bands - 1st - 2nd and 3rd
... Length of bullet from the nose to the grease groove band where the band is greater 373
You mentioned the base is 379
As for your breach seating of the bullet:
Harry Pope's recipe:
His 300gr bullet seated and engraved 1/16" in the leading bore cut
52fr FFg powder topped with a felt wad
Cartridge (not flared) seated with breach seater
As for your 62gr of powder ... I tried to put 62gr of FFg into a Starline 2.125 case. Filled to the mouth and had 13.3grs of powder still in the pan.
The choice is yours but I won't use 62 grs of powder