There are a few different strains...
I got a batch from moyers, some have black spots. I had to call and make sure they were actually broilers as I've never seen or heard of a broiler with black spots.
She informed me they are part of the Cobb line and some present black spots.
I'm talking dressed weights..... My birds always seem to be heavier than the chart. I know what you mean about them being different, I haven't had any as small as the ones you have now though.
I do them at 7 weeks.....
I get a 4.75lb average with a few pushing 6 lbs. they are pastured and do forage some at least until I fill the feeders
Seems like the charts are off a bit, by my calculations I should be able to average over 4lbs at the 6 week mark.