Don't forget that there is a 30 day to 6 month delay on ranking new domains now. I know in the past 301ing old quality niche related domains would bypass this delay, but it doesn't seem to do this any more - not for me anyway. Doesn't mean the 301s aren't as powerful as before though, just that the domain they're pointing to is still being held back while it matures.
Seeing this on one of my sites that im waiting to rank at the minute. I have 9 niche related domains redirected to it, and the site is now 10 weeks old. After the first burst of redirects it jumped to 2nd / 3rd page for all keywords for all keywords under 10K searches after a few weeks.
Anything over that wasn't to be seen for the first few weeks but in the last few weeks they've been slowly rising and the >10K searches keywords are now on between 30th and 60th positions.
I've gradually added a few hundred quality links over that time period as well, but i know the site wouldn't be where it was without the redirects. So i would say, just have patience and do what you usually do.. but give it time.