Does anyone know a place on the web where I can get the specs for drilling & tapping for scope mounts? I would like to find out about as many different guns and muzzleloaders as I can. locations, depth and thread size.
Thank for any help!

Get the Brownell's catalog - there is an enormous amount of information on such things.

www.brownells.com

Thanks Mike I might end up getting the catalog from Brownell's. I would really like to get started on my C.V.A and a Hawkins muzzleloader right away if I can find the info I need.

Most scope mount screws are 6-48 which is not a standard SAE size. So you'll likely have to order from Brownells anyway. Since a hole in a barrel can't go through, you'll need a bottom tap and a plug tap will be handy. Get a 6-48 die too. Next you'll need a #31 drill to make the hole and likely a #25 in case you have to drill a base.
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6876&title=WIRE+GAUGE+CARBON+TAPS+%26+DIES

Bye
Jack

This might be a good kit to start with.
DRILL & TAP KIT No. 2
http://www.brownells.com/aspx/NS/Store/ProductDetail.aspx?p=616&title=DRILL+%26+TAP+KIT+No.+2

Bye
Jack

Ya done good, Jack! :D