Ron,

I trust you are looking at APC electric props--- preferably the Thin Pusher ones. All of my APC electric props come with a set of adapters for different sized collet shafts. Usually one of these will fit the shaft and they simply plug into the rear of the prop hub. In the event that the main hole in the hub is itself too small I elect to carefully ream it to the correct size using a tapered ream and reaming from both the front and rear . This keeps the hole centered. I confess I have once or twice grabbed the correct sized drill and drilled the hole on my drill press. If you have a set or numbered drills you can work up to the correct size one number step at a time and it is unlikely that you will drill it off center.

My 2 cents,

John

To add to what Crist is saying: the APC prop holes are not necessarily concentric.  The back hole (the one that fits all the locating rings) is the precision hole -- the front hole is just for clearance to pass a shaft through.  So you don't want to drill out the front hole and use it to locate the prop, unless you're a good enough machinist to bring it into concentricity with the rear hole.

That's why Crist is recommending that you just drill the front for clearance, and use the rear hole (with a bushing) for location.

Is this true for all APC props, or just the electric series ?

I don't think the other props come with the locating ring, so no, it wouldn't apply.  It would only apply if the prop comes with a locating ring.

Tim,
Good information, I think could also effect the use of a balancer, we should probably do the balance with one of the sizing rings in place so as to have the prop mounted properly on the balancer shaft.

Best,           DennisT