Can someone tell me what size roll pin is used for the front sight of a 1911?  I don't know if it's standard across the board but I have a Dan Wesson VBob and a Sig Nitron with roll pins in the front sights.  I am going to change the sights on both but need to order new roll pins first.  I bought the replacement sights used so they did not come with roll pins.  Plus, I'm going to need to order a punch to remove them.  Any help would be greatly appreciated.

It can vary, but mostly 1/16" is what I see.

Once you tap the roll pin out you can reuse them, I usually toss them in the trash though.

Yes, I believe they are 1/16.  But, the problem I've had is that DW uses a non-standard location for the pin, which means that after market sights won't line up with the existing hole.  Check for this and don't be surprised.  And, don't try to make it work by just smashing it in there -- it won't.