Some years ago my dad loaned me his sporterized 03A3, his deer rifle in the 60s and 70s. I remember him working on loads and then going to the range to test them out. He had a load that would put 3 190 gr Boat Tail bullets under a quarter all day long, 3 under a dime on a good day. I remember the first time I shot the rifle and I was warned about the kick and scope bite by my friend's dad. It didn't kick any more or less than a 12 gauge (Dad had me shooting his old Ithaca since I was 8) and I had already read that scope bite can get you more shooting prone. I hit what I aimed at w/o a scope bite. Beautiful rifle, hand checkered by my friend's uncle.
Anyway, I asked Dad 8 years ago if I could try some cast boolits through his rifle and to my surprise he gave me the go ahead. The only mold I had was a Lee C309-150 RF I had bought to load for my wife's 30-30 Winchester 94 she inherited from her grandfather. I should probably bought the 170 RF but the 150 was on sale for 12.50 so what the heck. I first loaded with loads laddered up from 10 to 18 grains of Unique with great success. Well, my measure of success is hitting 'minute of soda can' at 100 yards, off hand. I could not miss all day. BTW, this was lube/sized .310 with Javalina.
This was before I got into powder coating, mostly for 300 BO at the time. Along the way, I bought an NOA 309-150 Spitzer using gas checks I made from aluminum flashing. My powder of choice was IMR4227 for the BO as it fully cycled the BO. The a year or so later I bought a Springfield M1A, and then a Sig 716 Patrol rifle, and a year later a Mossberg Scout Rifle. M1A fully cycled at 24 grains of IMR 4227 which a book load max was 30. I laddered up to 28 grains with consistent accuracy in all 3 308 rifles. Then, I decided to run 28 in the 03A3 knowing the pressure would be less due to the larger case capacity. Same 'minute of soda can' off hand.
I know this is about 30-06 and Unique, and I know I never have to worry about cycling a bolt gun. I will probably go back to Unique for my next 30-06 loads. I might also try Unique in a recently gifted 7.65x53 Argentine Mauser. Bore is pristine, stock has a couple of dings, bluing has a couple of worn spots, but all serial numbers match. I had it checked out, action is sound with no appreciable wear on the bolt and action which I was told it has not been cycled much. That coincides with the previous owner's claim that his brother in-law had only fired about 20 rounds, having purchased the rifle from importer in the mid 1950s supposedly unfired.
None of my load manuals list pressures for the 7.65, but plenty of resources indicate the case capacity is substantially similar to the 303 and 308, and that loads can be worked up using those loads as a starting point. I also know that most cast boolit loads are lower pressure than copper condom loads. I'm sure Unique will be to my go to for for the Argy with little worry of going overboard pressure-wise. Unique just works.