Chronograph Testing

First and foremost my heart aches for the folks and critters in the White Mountains of Arizona.  The 2011 Memorial Day weekend has started one of the worst fires in AZ history. The Wallow fire is consuming huge stands of Ponderosa Pines and destroying a lot of prime habitat for Arizona wildlife. We all need to pray for rain.
I was up near this area scouting for my elk hunt. It really does break my heart. But life goes on and this area will recover, eventually.
I took my bow back to PSE over the weekend. I wanted them to add a couple of pounds to my draw weight and look into a "creaking" noise from the upper limbs. Zack and the staff at PSE were very helpful in explaining how the creak was a limb binding issue.  They are going to order the parts and take care of it in a simple 1/2 hour procedure next week.
They added the 2 1/2 lbs to my draw weight so I'm now pulling 65 pounds. I set up a chronograph to shoot arrows through in order to understand my arrow speed. Right now my target arrows average 355 grains including a 125 grain field point. The hunting arrows I am considering are 405 grains with a 100 grain field point.
I shot from 10 yards through the chronograph and had speeds of 298 f.p.s. for the 355 grain arrows and 282 f.p.s. for the 405 grain arrows. Online I found some Kinetic Energy Charts http://www.redhawk-archery.com/ke.php and plugged in my arrow weight and speed and found the 355 grain arrows produce around 70 foot pounds of energy. The 405 grain arrows approximately 71.5 lbs of energy.
Not much difference is there? I need to shoot at distance to see the arrow drop for a 50 grain heavier arrow when held at the same point. Overall I am very happy with my bow and my shooting!