I bought a used Uberti Hi Wall in 45-70 at a good price to plink with.  I loaded up some cartridges and headed to the range.  The rifle would not hit the primers hard enough to fire.  The first primers were Winchester LR so switched to Federal LP and it fired.  Got new mainspring installed and still light hits on Rifle primers.  I am going to find some Federal LR to try.  Nothing seems to be binding and hammer swings free.  Firing pin is fine and protrusion is good and no burrs in block.  Headspace is good also.  It just seems as though main spring does not have enough power.  Any one worked on these or have any ideas?  Uberti copied the original design pretty much that is why I bought it.  Charlie

Thanks for the reply,  I have done all that and still no go.  Charlie

Vaguely recall a problem where the tang sight screws being to long and causing an issue like this. May be old brain cells doing the recalling though!