Hi Guys,
This is my first post on Graybeard Outdoors.  I am a recent convert from upland bird hunting to squirrel and other small game hunting.  I hunt with my West Siberian Laika, a kind of all-purpose dog developed over the centuries by several indigenous Siberian tribes.  In the U.S. they are mostly used for squirrel hunting.  I like general purpose things (don't ask why, I'm not sure I can answer).  With him, I have opportunities for squirrel, grouse, woodcock.  When out with him, as he is very quiet, I see deer.  I am very attracted to the whole notion of the BBF or over/under rifle-shotgun combination gun.  Although I would love a Blaser B95 or Krieghoff Ultra, I don't think it is in the financial cards any time soon.  I do think the Marocchi 512 Finnclassic (or Valmet 412) is within my budget if I sell off some other firearms.  Here is my main question.  Does anyone make a 22LR insert that would work in the shotgun barrel of the FinnClassic?  Or, alternatively, can the .222 Remington or 6.5x55 Swede be sufficiently down-loaded to be useful and not destructive on small game?  I have secondary questions if you don't mind.  Does anyone have experience using the 512/412 with shotgun barrels on upland birds.  Is it lively and well-balanced in the hands, or more heavy and clunky?  Lastly, what does a plain-jain Krieghoff Ultra cost?  I have checked Gunbroker, Gunsamerica and Auctionarms and do not find one listed as a gauge.  Thanks in advance guys for any insight you can provide.  
Bonasus