VLD/Non-VLD starting velocity?

[1shot]

After a search, which revealed little, I'll ask the question to those in the know. All things being equal, as in same case, primer, powder and charge, rifle, etc. Is there one bullet that will have a starting velocity higher that another, relative to its profile? To be more specific, the difference between a Lapua Scenar 6.5/139gr. and a JLK 140 gr. is .055 more bearing surface on the Lapua. Does the increase in bearing surface slow the bullet in the barrel because of increased friction; or does the increased friction build more pressure, giving it a higher starting velocity?
Thanks in advance for your help,
Lloyd