There's a group like that on yahoo groups for both lead bullets and bullets with jackets on them, it's for traditional single shot rifles only, no bolt actions, check it out at 

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It's not very active but it's probably because not many know about it.
  O C S

Hi Barney.
I checked the link that Old Center Shot provided and found a lot to look at, John Louis up loaded a bunch of good info on the 32-40 and the 38-55, plus  the Don Miller Twist Rate Rule and a Lead Alloy Calculator.

Ira Paine listed just about anything anyone would want to know about Unertl Target Scopes, and there are over 100 Photos of all kinds and types of Single Shot Rifles, older and newer ones.

I see it's a little light on info about shooting SS rifles with jacketed bullets but it's allowed on that site so all you have to do is ask about the info your looking for. 

There is another site about the Ruger # 1 and # 3 Single Shot but it's a site that's dedicated to the Ruger SS only, has lots of very good info on shooting and collecting them if that's what your interested in, you can check it out at : (You need to Login or Register to view media files and links)

Just what is it your looking for ?.
  Regards
   H, M. Pope