After a lot of years as a CAS Gunsmith, I have not encountered a problem like yours, so I have to ask some questions.
Are your guns stock?? Have your Main Springs been reground?? Has the bolt been altered?? Has the hammer cam been altered??
It's not uncommon to encounter excess wear on the hammer cam of a Uberti SA. Although, not usually within the firs year of service. Most go thru years of hard use before the hammer cam wears to the extent it must be drilled out and replaced or a new hammer put in the gun.
Same Same for stock Main Springs. Normally, the Main Spring is good almost forever. If it is overheated when being reground, it may not be a spring. If it is an aftermarket spring, I'd check with the supplier, to see if others are having the same problem. I once ordered a hundred springs from a jobber and all the springs were ...... not springs. the jobber refused to exchange or refund. New jobber.
Undue wear can occur to the hammer cam if the bolt has been improperly altered. Sticking in half cock would indicate a problem with the bolt and it's relationship to the hammer cam. Again, were those parts worked on??
Your ammunition should have no bearing on the problems you describe. My first guess would be untrained finger poking in the lock works of your guns.
Coffinmaker
PS: If the fix was brought to me, my first step would be to dump the parts of the lock works in the trash and start over. I'm retired now though