I had a 3rd generation Colt SAA for years and I still own 2 S&Ws, a 24 and a 21. I use a 250 grain bullet and 8 grains of Unique in my S&Ws and I used the same in the Colt. I can't say for certain about the strength of the Uberti, and rumors say their cylinders are not made of the same steel as a real Colt or a S&W, and I have been told they are very soft. I can't confirm that myself, but it may be true. If so I would not go as hot as may load, but who to ask about "blow-up tests" I have no idea.
The 8 grains of Unique load with a 250 grain bullet was/is very good in all my 44 specials and the cases would just about fall from the guns, but it is over the max loads according to some manuals. I believe this is because back at the turn of the century the 44 special and the 44 Russian shared the same ballistics and the pressures were set because of existing parameters of velocities and bullet weights from the Black powder days, not because of the safe upper limits of the guns they were chambered in. E. Keith used 18.5 gr of 2400 with 240 grain bullets for many years in S&W 44 special revolvers and did fine, and the old colts, even the 2nd Generation colts were known to be as strong or stronger then the S&Ws. That load is WAY hotter then any spec set by the makers of the ammo, which were written down in the days well before WW1.
All that aside, I can say that in every 44 Spl I have ever used this load in including about 6 others that belong to friends of mine, the accuracy is simply outstanding, with ragged hole groups at 20 yards being common.
Lead 250gr bullet? If so, cast by you or bought? Gas check? Hardness?
I’ve been shooting the 200gr XTP, but my supply is drying up. I have a boatload of Unique. Thanks for your time.
