Blaster Bolts don't move at lightspeed, unless you mean Turbolasers, those move at lightspeed.
Like most energy weapons, turbolasers fire invisible energy beams at lightspeed. The 'bolt effect' seen when a turbolaser is fired is actually a glowing pulse that travels along the beam at less than lightspeed.- Taken from Fact File 47
Turbolaser shots are lightspeed, the shot being invisible but the thing actually seen is slower.
The same basic principals apply for blaster shots, but they wouldn't move at lightspeed. I would put them around bullet speed AT THE LEAST.
Of course, the fastest moves in the galaxy couldn't block a blaster's particle beam or a projectile from a slugthrower.- Taken from Medstar: Battle Surgeons
I take the 'fastest moves' being what normal people are capable of, seeing as we see Jedi being fast enough to block/deflect multiple blaster shots.
So...really I put Blaster Bolt speed at the very LEAST on bullet speed level, I actually would put it higher considering blaster tech > slugthrower tech(pretty much what IRL we have) but bullet speed is fine.
I found it actually:
"Energy weapons fire invisible energy beams at lightspeed. The visible "bolt" is a glowing pulse that travels along the beam at less than lightspeed. Therefore, targets can explode instants before the "bolt" actually arrives." --Taken from Attack of the Clones Incredible Cross-Sections: The Definitive Guide to the Craft from Star Wars: Episode II
Originally posted by The Merchant
I found it actually:"Energy weapons fire invisible energy beams at lightspeed. The visible "bolt" is a glowing pulse that travels along the beam at less than lightspeed. Therefore, targets can explode instants before the "bolt" actually arrives." --Taken from Attack of the Clones Incredible Cross-Sections: The Definitive Guide to the Craft from Star Wars: Episode II
Which is speaking of Turbolasers, which the Fact File quote pretty much says the same thing, not regular blaster shots from handheld blasters.