JJ - unless your chronograph is suspect, I would say around a 200 fps spread on both calibres is not good. People using a chronograph are usually looking for a spread of no more than 40 fps. It could of course be that just one round was low and one high - if you were to deduct the lowest and the highest then divide by 8 how dramatically would that effect spread. Bear in mind the SD (standard deviation) is the all important figure.
For normal live quarry out to say 200 yds your figures are not too concerning, however at extended ranges I would predict accuracy will fall off.