Castlead,

Your best bet will be to buy an old action and reverse engeneer it. The Jones underlever is pretty simple once you see it in detail, and if you don't make it with self cocking locks, you have a very simple action.

Steel of choice would be 8620. Plan on case hardening it after engraving. There are several shops that you can send it to for color case hardening, Doug Turnbull being at the head of the pack.

Lock parts such as springs, sears, firing pins and some screws I make from 1084 steel.

You can build a 30-30 on a nice petite action that will feel alive.

I wish I knew of a source for machinist drawings. Would have saved me hundereds of hours. Lots if inexpensive shotguns here to use as a pattern though.

http://www.simpsonltd.com/index.php?cPath=350_354&osCsid=9d80919c17709696f93daf6062ae559c

Best of luck!!