Reloading .303 British : Them Nasty WW2 Winchester rounds showed up!!

I have one box that will remain sealed so I will never be able to determine consistent velocities or accuracy but, knowing that there is an averaged difference of a 7.4grn spread within each 20 round box, it is suffice to say that accuracy from these rounds would be abysmal. The current reloads have known velocities and accuracy from past experience. 

39.0grns of Norma 202

210M primers 

.311 FMJBT 

OAL 3.025"

Averaged chronographed FPS 8ft from muzzle= 2612

Averaged horizontal and vertical spread of a ten shot group at 100 yards= 1.31"

At that was with a scoped rifle with a used barrel and using a sandbag for support. 

It stands to reason these rounds will be as accurate or better when fired through a rifle with a "new" barrel...