Really a little surprised that it is that much difference, but alot of factors may be involved. Probably a different grip on the Apache, and I would bet your draw length is less with that than with the standard BW grip, possibly an inch or more. I would have someone mark the arrows when I was at full draw with each bow, and actually put them on a scale to see the actual poundage at your draw.
I am a little surprised that a bow that shoots 15fps slower would be able to use the same arrows, especially since it is likely cut further from center than the BW. Tuning might come into play as well. Numbers like you are getting would be a little more expected with a D shaped longbow.