|
Just about any good gunsmith with a lathe and the appropriate chambering reamers ought to be able to make adapters like you describe or modify .32 ACP adapters. (.32 ACP uses a .308 bullet and those adapters work fine in .30 rifles.) I think the cost of making an adapter would, as they say, be off-putting.
It would depend somewhat on whether the adapter is to be rifled or only smoothbore from the bullet of the smaller cartridge to the throat of the barrel. Note that there could be trouble with higher pressure cartridges like the .30 Mauser, as the adapter is not fully supported and could bulge.
Jim
|