Tuning pin drilling?

[jimialeggio5 at comcast.net]

This has me baffled.

I'm drilling Delignit blocks for tuning pins.  2/0 pins.  2 step hole, aka Ron's 
2 step drilling procedure, with 
modifications to suit my equipment and personality.  

Block on the bench on an adjustable beveled bed. 

1st pass, drill hole @ 1/4" using a fixture I made which holds a 1/4" drill 
bushing right up close and personal 
to the block to stabilize the initial hole and make up for the inaccuracy of my 
press.  
2nd pass with a slightly shy "I" bit (.271) which has a non-cutting 1/4" pilot 
ground on the 1st 1/2"
of the tip to center the 2nd pass. I dust the pins with rosin before driving.

Holes are nice and consistent as proved by consistent torques (130in/lb) on .282 
mic'd pins.

Here's the weird part. I mic the pins and am mostly only using the pins that are 
either .282, or slightly light  
at about .281 or .2805.  When I drive both the .282 and the light pins the light 
pins consistently torque at 
about 20-25 lbs more than the .282 pins.  

This makes absolutely no sense to me.   
      
Any ideas why this is happening?

Jim I