In case some of you do not realize the Easton arrow numbers designate measurements. The first 2 numbers are 64ths of an inch outside and the second set of numbers are the wall thickness in thousandths. So a 2216 is 22/64" outside with a .019" wall.
The diameter of the hole inside the alum shaft is the outside dimension of the arrow minus twice the wall thickness.
21/64=.328"
22/64=.343"
Just subtract 2 times the wall thickness of you arrow for the inside dimension.
2115 is .328 O.D.-.030(2x.015" wall)= .298" I.D.
2117 is .294" I.D.
2213 is .317" I.D.
2216 is .311" I.D.
2219 is .305" I.D.
Hope this helps....and check my math
I have noticed the outside dimensions of carbon arrows are different even if they are the same spine number, especially if they do or do not have a silk screened wood grain or camo on them.
I guess I'm suggesting you measure the carbons before making up the aluminum sleeves.
Rick