You say there was an "overlap problem...". 

So, just asking, do you feel they spread on too wide of swath setting @ 70'? What would your suggestion have been? 

I believe some machines have larger pans and can spread wider swaths than others, even while maintaining less spinner rpms.

For other posters that say spinner spreaders are wrong compared to air spreaders, I would suggest that is a regional thing. In our area of NE IL I'm not sure that any air boom spreaders exist. There were some years ago when they first emerged, but most have been replaced by spinners. I guess we could be wrong here, but that's the reality of it.