What are you measuring them with? I had the same ? when I built the latest engine. I used the cap screw type and their relaxed were spread out as well.
I was told to 1) measure relaxed anyway, note reading 2) stretch to .0063
3) take em off and measure again with the same dial, note reading. If it has increased by more than .001", round file. IMO- these bolts out of the box will vary in their length, that is why ARP has you measure and write down their length so you can compare if you ever do a tear down/rebuild.